Research Publications



JOURNAL: Sleep Health 3 (2017) 6–19
TITLE: National Sleep Foundation's sleep quality recommendations: first report
AUTHOR(S): Maurice Ohayon, Emerson M.Wickwire, Max Hirshkowitz, Steven M. Albert, Alon Avidan, Frank J. Daly, Yves Dauvilliers, Raffaele Ferri, ConstanceFung, David Gozal, NancyHazen, AndrewKrystal, Kenneth Lichstein, Monica Mallampalli, Giuseppe Plazzi, Robert Rawding, Frank A. Scheer, Virend Somers, Michael V. Vitiello


Objectives: To provide evidence-based recommendations and guidance to the public regarding indicators of good sleep quality across the life-span.

Methods: The National Sleep Foundation assembled a panel of experts from the sleep community and representatives appointed by stakeholder organizations (Sleep Quality Consensus Panel). A systematic literature review identified 277 studies meeting inclusion criteria. Abstracts and full-text articles were provided to the panelists for review and discussion. A modified Delphi RAND/UCLA Appropriateness Method with 3 rounds of voting was used to determine agreement.

Results: Formost of the sleep continuity variables (sleep latency, number of awakenings N5 minutes, wake after sleep onset, and sleep efficiency), the panel members agreed that these measures were appropriate indicators of good sleep quality across the life-span. However, overall, there was less or no consensus regarding sleep architecture or nap-related variables as elements of good sleep quality.

Conclusions: There is consensus among experts regarding some indicators of sleep quality among otherwise healthy individuals. Education and public health initiatives regarding good sleep quality will require sustained and collaborative efforts from multiple stakeholders. Future research should explore how sleep architecture and naps relate to sleep quality. Implications and limitations of the consensus recommendations are discussed.




JOURNAL: J Clin Psychiatry, 2016
TITLE: High Rates of Psychiatric Comorbidity in Narcolepsy
AUTHOR(S): Chad M. Ruoff, Nancy L. Reaven, Susan E. Funk, Karen J. McGaughey, Maurice M. Ohayon, MD, Christian Guilleminault, Jed Black


Objective: To evaluate psychiatric comorbidity patterns in patients with a narcolepsy diagnosis in the United States.

Methods: Truven Health Analytics MarketScan Research Databases were accessed to identify individuals ≥ 18 years of age with ≥ 1 ICD-9 diagnosis code(s) for narcolepsy continuously insured between 2006 and 2010 and nonnarcolepsy controls matched 5:1 (age, gender, region, payer). Extensive subanalyses were conducted to confirm the validity of narcolepsy definitions. Narcolepsy subjects and controls were compared for frequency of psychiatric comorbid conditions (based on ICD-9 codes/Clinical Classification Software [CCS] level 2 categories) and psychiatric medication use.

Results: The final population included 9,312 narcolepsy subjects and 46,559 controls (each group, mean age = 46.1 years; 59% female). All categories of mental illness were significantly more prevalent in patients with narcolepsy versus controls, with the highest excess prevalence noted for CCS 5.8 Mood disorders (37.9% vs 13.8%; odds ratio [OR] = 4.0; 95% CI, 3.8–4.2), CCS 5.8.2 Depressive disorders (35.8% vs 13.0%; OR = 3.9; 95% CI, 3.7–4.1), and CCS 5.2 Anxiety disorders (25.1% vs 11.9%; OR = 2.5; 95% CI, 2.4–2.7). Excess prevalence of anxiety and mood disorders (narcolepsy vs controls) was higher in younger age groups versus older age groups. Psychiatric medication usage was higher in the narcolepsy group versus controls in the following categories: selective serotonin reuptake inhibitors (36% vs 17%), anxiolytic benzodiazepines (34% vs 19%), hypnotics (29% vs 13%), serotonin-norepinephrine reuptake inhibitors (21% vs 6%), and tricyclic antidepressants (13% vs 4%) (all P values < .0001).

Conclusions: Narcolepsy is associated with significant comorbid psychiatric illness burden and higher psychiatric medication usage compared with the non-narcolepsy population.




JOURNAL: Neurology® 2016;87:1–8
TITLE: Refining duration and frequency thresholds of restless legs syndrome diagnosis criteria
AUTHOR(S): Maurice M. Ohayon, Kanika Bagai, Laura W. Roberts, Arthur S. Walters, Cristina Milesi


Objective: This study assesses the prevalence of restless legs syndrome (RLS) using DSM-5 criteria and determines what is the most appropriate threshold for the frequency and duration of RLS symptoms.

Methods: The Sleep-EVAL knowledge base system queried the interviewed subjects on life, sleeping habits, and health. Questions on sleep and mental and organic disorders (DSM-5, ICD- 10) were also asked. A representative sample of 19,136 noninstitutionalized individuals older than 18 years living in the United States was interviewed through a cross-sectional telephone survey. The participation rate was 83.2%.

Results: The prevalence of the 4 leg symptoms describing RLS occurring at least 1 d/wk varied between 5.7% and 12.3%. When the frequency was set to at least 3 d/wk, the prevalence dropped and varied between 1.8% and 4.5% for the 4 leg symptoms. Higher frequency of leg symptoms was associated with greater distress and impairment with a marked increase at 3 d/wk. Symptoms were mostly chronic, lasting for more than 3 months in about 97% of the cases. The prevalence of RLS according to DSM-5 was 1.6% (95% confidence interval 1.4%–1.8%) when frequency was set at 3 d/wk. Stricter criteria for frequency of restless legs symptoms resulted in a reduction of prevalence of the disorder. The prevalence was further reduced when clinical impact was taken into consideration.

Conclusions: In order to avoid inflation of case rates and to identify patients in whom treatment is truly warranted, using a more conservative threshold of 3 times or greater per week appears the most appropriate.




JOURNAL: larevuedupraticien Vol. 66 _ Juin 2016
TITLE: La plainte « somnolence excessive » concerne un quart de la population
AUTHOR(S): Maurice M. Ohayon, Yves Dauvilliers, Cristina Milesi


Avec la mise à jour récente des classifications de l’American Psychiatric Association et de l’Association internationale des troubles du sommeil, les chapitres consacrés aux hypersomnies et à la narcolepsie ont été profondément remaniés.1, 2 Des changements importants ont été faits dans le Manuel diagnostique et statistique des troubles mentaux (DSM) en vue d’améliorer la définition et l’identification des hypersomnies, qui ont été renommées « hypersomnolences ».

Le fondement de ce changement d’appellation a des racines étymologiques et scientifiques. Bien que, étymologiquement, hypersomnie signifie « dormir en excès », la définition de l’hypersomnie dans les manuels de classification était celle de la somnolence excessive, avec pour conséquence la confusion entre le « dormir trop » et le « somnoler trop ». Sur le plan scientifique, les études épidémiologiques ont aussi alimenté cette confusion dans les taux de prévalence liés aux hypersomnies. En fait, la somnolence excessive est :
– une caractéristique essentielle dans l’hypersomnie et la narcolepsie ;
– une caractéristique associée pour le syndrome d’apnées obstructives du sommeil et pour les troubles du rythme circadien du sommeil ;
– une conséquence de l’insomnie ou de la privation de sommeil ;
– ou un effet secondaire d’un traitement.

Tenter d’identifier le rôle de chaque maladie où l’hypersomnolence est impliquée peut ainsi se révéler difficile et complexe ; toutefois cette démarche peut se révéler importante à des fins épidémiologiques et cliniques.

La somnolence excessive est actuellement caractérisée par deux principaux symptômes : la quantité excessive de sommeil, définie comme une période de sommeil principale prolongée ou la présence d’une ou plusieurs siestes ; et une mauvaise qualité de l’éveil. Cette précision nosographique est essentielle tant les terminologies employées sont multiples. Plusieurs concepts, souvent interchangeables, étaient utilisés pour définir cet état de somnolence dont la plupart se réfèrent à la somnolence diurne. Ainsi, la somnolence, la somnolence excessive, la somnolence diurne excessive, la somnolence subjective, la somnolence objective, l’hypersomnolence, l’hypersomnie, la capacité à s’endormir, l’incapacité à rester éveillé, l’hypovigilance, la fatigue, la fatigue excessive… sont souvent employées pour définir cet état. Cela est d’autant plus important lorsqu’il s’agit de distinguer l’hypersomnolence de la fatigue caractérisée par une sensation d’affaiblissement physique ou psychique, survenant le plus souvent à la suite d’efforts qui en imposent l’arrêt. La fatigue est souvent réversible au moins partiellement avec la mise au repos.




JOURNAL: Sleep Health 2 (2016) 94–99
TITLE: Sleep-deprived motor vehicle operators are unfit to drive: a multidisciplinary expert consensus statement on drowsy driving
AUTHOR(S): Charles A. Czeisler, Emerson M.Wickwire, Laura K. Barger, PhDa,b, William C. Dement, Karen Gamble, Natalie Hartenbaum, Maurice M. Ohayon, Rafael Pelayo, Barbara Phillips, Kingman Strohl, Brian Tefft, ShanthaM.W. Rajaratnam, Raman Malhotra, KaitlynWhiton, Max Hirshkowitz


Objectives: This article presents the consensus findings of the National Sleep Foundation Drowsy Driving Consensus Working Group, which was an expert panel assembled to establish a consensus statement regarding sleep-related driving impairment.

Methods: The National Sleep Foundation assembled a expert panel comprised of experts from the sleep community and experts appointed by stakeholder organizations. A systematic literature review identified 346 studies that were abstracted and provided to the panelists for review. A modified Delphi RAND/UCLA Appropriateness Method with 2 rounds of voting was used to reach consensus.

Results: A final consensus was reached that sleep deprivation renders motorists unfit to drive a motor vehicle. After reviewing growing evidence of impairment and increased crash risk among driverswho obtained less than optimal sleep duration in the preceding 24 hours, the panelists recognized the need for public policy guidance as to when it is certainly unsafe to drive. Toward this end, the panelists agreed upon the following expert consensus statement: “Drivers who have slept for two hours or less in the preceding 24 hours are not fit to operate a motor vehicle.” Panelists further agreed that most healthy driverswould likely be impaired with only 3 to 5 hours of sleep during the prior 24 hours.

Conclusions: There is consensusamong experts that healthy individualswho have slept for 2 hours or less in the preceding 24 hours are too impaired to safely operate amotor vehicle. Prevention of drowsy driving will require sustained and collaborative effort from multiple stakeholders. Implications and limitations of the consensus recommendations are discussed.




JOURNAL: Sleep, 2016
TITLE: Incidence Of Narcolepsy Symptoms Among The Family Members Of Narcoleptic Probands: A Longitudinal Study.
AUTHOR(S): Maurice M. Ohayon


Introduction: Narcolepsy is a rare disabling sleep disorders characterized by excessive daytime sleepiness (EDS), sudden daytime sleep attacks, often accompanied by cataplexy and sleep paralysis, and disturbed nocturnal sleep. The disorder has its likely origins in certain gene defects that trigger an autoimmune response. The genetic etiology of the disease is also confirmed by the higher prevalence of the disease among close relatives of narcoleptics. The objective of this study is to estimate the incidence of narcoleptic symptoms in a longitudinal study of narcoleptic family members.

Methods: 4,397 individuals were interviewed by telephone with the SleepEVAL system. The study sample included 358 subjects diagnosed with narcolepsy and 4039 family members evaluated at 3 to 5 yearintervals.

Results: At followup, 192 family members were deceased and 54 couldn’t be interviewed due to debilitating or terminal disease. The incidence of narcolepsy among family members was 1.2%, two to three times higher than in the control group. Half of the family members reported moderate to severe sleepiness at followup, and, among these, 34.2% reported an increase in their sleepiness. Incidence of excessive sleepiness was highest among thirddegree relatives. Incidence of sleep paralysis was highest among seconddegree relatives. At followup, the frequency of sleep paralysis increased in 57% and decreased in 19% of cases. The predictors of developing narcolepsy at followup were presence of sleep paralysis at the first interview (AOR: 4.73) and presence of excessive sleepiness (AOR: 4.95).

Conclusion: Risks for narcolepsy are high among family members. However, incidence of different narcoleptic symptoms is not the same among first, secondand thirddegree relatives. Support (If Any): Educational grant from Jazz Pharmaceuticals.




JOURNAL: Neurology, 2016
TITLE: Narcolepsy Symptomatology Evolution in a Longitudinal Study of a Cohort of Narcoleptic Family Members
AUTHOR(S): Maurice M. Ohayon


Objective: To study the evolution of narcolepsy symptoms, sleep habits, sleep and mental disorders, in a cohort of narcoleptics and their family members.

Background: Narcolepsy is a rare sleep disorder affecting around 0.04% of the general population. Many studies point to a genetic component in the disease, reporting 8% to 12% of individuals with narcolepsy having a close relative with the disease.

Methods: A cohort of 4039 family members of 358 narcoleptics was interviewed twice, between 2011 and 2015, with the Sleep-EVAL system. A control group of 178 spouses and roommates was also interviewed twice.

Results: The incidence of narcolepsy among family members was 1.2%. At follow-up, 192 family members were deceased and 54 couldn’t be interviewed due to debilitating or terminal disease. Half of the family members reported moderate to severe sleepiness at follow-up. Of them, 34.2% reported an increase in their sleepiness. Predicting factors of excessive sleepiness at follow up were being a family member (AOR: 5.8 to 10.2), cataplexy-like symptoms (AOR: 1.7), and presence of a mental disorder (AOR: 1.6). 12.2% reported to have experienced sleep paralysis at the initial interview. At follow-up, 57% of the family members reported an increase in frequency in sleep paralysis, while a decrease was reported by 19% of the cases. The predictors of developing narcolepsy at follow-up were presence of sleep paralysis at the first interview (AOR: 4.73) and presence of excessive sleepiness (AOR: 4.95).

Conclusions: Among family members of narcoleptic individuals there is a high risk of narcolepsy. Additionally, excessive sleepiness is more often chronic and increases in severity over time.

Study Supported by: a grant from NIH (R01NS044199), the Arrillaga Foundation and unrestricted educational grant from Jazz Pharmaceuticals.




JOURNAL: SLEEP, Vol. 39, No. 6, 2016
TITLE: Artificial Outdoor Nighttime Lights Associate with Altered Sleep Behavior in the American General Population
AUTHOR(S): Maurice M. Ohayon, Cristina Milesi


Study Objectives: Our study aims to explore the associations between outdoor nighttime lights (ONL) and sleep patterns in the human population.

Methods: Cross-sectional telephone study of a representative sample of the general US population age 18 y or older. 19,136 noninstitutionalized individuals (participation rate: 83.2%) were interviewed by telephone. The Sleep-EVAL expert system administered questions on life and sleeping habits; health; sleep, mental and organic disorders (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision; International Classification of Sleep Disorders, Second Edition; International Classification of Diseases, 10th Edition). Individuals were geolocated by longitude and latitude. Outdoor nighttime light measurements were obtained from the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS), with nighttime passes taking place between 19:30 and 22:30 local time. Light data were correlated precisely to the geolocation of each participant of the general population sample.

Results: Living in areas with greater ONL was associated with delayed bedtime (P < 0.0001) and wakeup time (P < 0.0001), shorter sleep duration (P < 0.01), and increased daytime sleepiness (P < 0.0001). Living in areas with greater ONL also increased the dissatisfaction with sleep quantity and quality (P < 0.0001) and the likelihood of having a diagnostic profile congruent with a circadian rhythm disorder (P < 0.0001).

Conclusions: Although they improve the overall safety of people and traffic, nighttime lights in our streets and cities are clearly linked with modifications in human sleep behaviors and also impinge on the daytime functioning of individuals living in areas with greater ONL.




JOURNAL: SLEEP, Vol. 37, No. 3, 2014
TITLE: Increased Mortality in Narcolepsy
AUTHOR(S): Maurice Ohayon, Jed Black, Chinglin Lai, Mark Eller, Diane Guinta, Arun Bhattacharyya


Objective: To evaluate the mortality rate in patients with narcolepsy.

Design: Data were derived from a large database representative of the US population, which contains anonymized patient-linked longitudinal claims for 173 million individuals.

Setting: Symphony Health Solutions (SHS) Source Lx, an anonymized longitudinal patient dataset.

Patients/Participants: All records of patients registered in the SHS database between 2008 and 2010.

Interventions: None

Measurements and Results: Identification of patients with narcolepsy was based on ≥ 1 medical claim with the diagnosis of narcolepsy (ICD-9 347.xx) from 2002 to 2012. Dates of death were acquired from the Social Security Administration via a third party; the third party information was encrypted in the same manner as the claims data such that anonymity is ensured prior to receipt by SHS. Annual all-cause mortality rates for 2008, 2009, and 2010 were calculated retrospectively for patients with narcolepsy and patients without narcolepsy in the database, and standardized mortality ratios (SMR) were calculated. Mortality rates were also compared with the general US population (Centers for Disease Control data). SMRs of the narcolepsy population were consistent over the 3-year period and showed an approximate 1.5-fold excess mortality relative to those without narcolepsy. The narcolepsy population had consistently higher mortality rates relative to those without narcolepsy across all age groups, stratified by age decile, from 25-34 years to 75+ years of age. The SMR for females with narcolepsy was lower than for males with narcolepsy.

Conclusions: Narcolepsy was associated with approximately 1.5-fold excess mortality relative to those without narcolepsy. While the cause of this increased mortality is unknown, these findings warrant further investigation.




JOURNAL: Annals of Neurology Vol 76 (suppl 18) 2014
TITLE: Pain and Sleep Disturbances in the United Kingdom
AUTHOR(S): Maurice M. Ohayon, Laura W. Roberts.


Introduction: Clinical studies have shown that sleep disturbances are common in individuals experiencing pain. This study assesses the occurrence of sleep disturbances in individuals with chronic pain in the general population of UK.

Methods: A random sample of 2,946 participants (>515 years), representative of the UK, was interviewed by telephone. Chronic pain duration was set at three months. Frequency, severity, duration, impacts on functioning, and health care utilizations were investigated. Sleep and psychiatric disorders were assessed using DSM-IV-TR criteria and ICSD-2. ICD-10 was used for organic diseases.

Results: Overall, 31.6% of the sample reported having chronic pain. After adjusting for age and gender, sleep disturbances occurring at least three nights/week for at least 1 month were more frequent individuals with chronic pain compared to Non-pain: Difficulty initiating sleep (OR: 2.0[1.5-2.6]; nocturnal awakenings (OR: 2.1[1.8-2.5]); nonrestorative sleep (OR: 2.7[2.1–3.6]) and excessive sleepiness (OR: 2.4[1.9-2.9]). Sleep duration was also shorter. Impacts on daytime functioning was greater when sleep disturbances were accompanied with chronic pain.

Conclusions: These results show that chronic pain has an important role on sleep quality. Insomnia individuals with chronic pain have greater impairment in their daily life than those without pain. Study supported by: Pfizer Inc.




JOURNAL: Annals of Neurology Vol 76 (suppl 18) 2014
TITLE: Evolution of Narcolepsy Symptomatology and Mortality in a Longitudinal Study of Family Members of Narcoleptic Individuals
AUTHOR(S): Maurice M. Ohayon


Introduction: Genetic etiology in narcolepsy has been documented: Multi-family cases can be found in 8% to 10% of narcoleptics’ families. It exists however nearly no longitudinal information on the evolution of narcolepsy symptoms in the narcoleptics’ families.

Methods: Information on 2,010 individuals was collected: 300 subjects with narcolepsy and 1,710 family members at 3 to 5 year-intervals. In both cases, interviews were conducted by telephone with the Sleep-EVAL system.

Results: At the follow-up, 72 family members were deceased and 37 couldn’t be interviewed due to debilitating or terminal disease. 19 family members developed narcolepsy. The incidence was 1.2%. 50.1% of the family remembers reported moderate to severe sleepiness at follow-up. Of them, 34.2% reported an increase in their sleepiness; it was substantial for 11.7% of the family members. 12.2% experienced sleep paralysis at the initial interview. At follow-up frequency increased in 57% and decreased in 19% of cases.

Conclusion: Risks for narcolepsy are high in family members. Prevalence of excessive sleepiness is about two times higher in narcoleptic family members compared to the general population.




JOURNAL: 2015 American Neurological Association
TITLE: Prevalence and Incidence of Narcolepsy in a Longitudinal Study of Family Members of Narcoleptic Individuals
AUTHOR(S): Maurice M. Ohayon


Genetic etiology in narcolepsy has been documented: Multifamily cases can be found in 8% to 10% of narcoleptics’ families. It exists however nearly no longitudinal information on the evolution of narcolepsy symptoms in the narcoleptics’ families. 4,397 individuals were interviewed: 358 subjects with narcolepsy and 4039 family members at 3 to 5 year-intervals. In both cases, interviews were conducted by telephone with the Sleep-EVAL system. At the follow-up, 192 family members were deceased and 54 couldn’t be interviewed due to debilitating or terminal disease. The incidence of narcolepsy among family members was 1.2%. 50.1% of the family remembers reported moderate to severe sleepiness at follow-up. Of them, 34.2% reported an increase in their sleepiness. 12.2% experienced sleep paralysis at the initial interview. At follow-up frequency increased in 57% and decreased in 19% of cases. The predictors of developing narcolepsy at follow-up were presence of sleep paralysis at the first interview (AOR: 4.73) and presence of excessive sleepiness (AOR: 4.95). Risks for narcolepsy are high in family members. Prevalence of excessive sleepiness is about two times higher in narcolpetic family members compared to the general population.

Study supported by: Educational grant from Jazz Pharmaceuticals.




JOURNAL: Annals of Neurology Vol 78 (suppl 19) 2015
TITLE: Influence of Nighttime Lights on the Sleep of the General Population
AUTHOR(S): Maurice M. Ohayon, Cristina Milesi.


Artificial lights have introduced a wide range of benefits for people, but it has also profoundly affected our biology by modifying the natural light-dark cycle. Our study aims to show the effects of exposure to nighttime light radiance (NLR) on the circadian rhythms of the human population. A sample of 15,863 individuals representative of the U.S. general population was interviewed by telephone using the Sleep-EVAL expert system. Data collected during the interviews included sleeping habits and sleep disorder diagnoses. Individuals were geolocated by longitude and latitude; NLR was obtained from the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS). Exposure to greater NLR caused a shift in the circadian rhythm by delaying bedtime (p <0.0001) and wake up time (p<0.0001), shortening the sleep duration (p<0.01) and increasing daytime sleepiness (p<0.0001). Exposure to greater NLR also increased the dissatisfaction with sleep quantity and quality (p<0.0001) and the likelihood of having a Circadian Rhythm Disorder (p<0.0001). Although it improves the overall safety of people and traffic, nighttime lights in our streets and cities clearly impacts on human circadian rhythms and affects also the daytime functioning of individuals exposed to greater NLR.




JOURNAL: Sleep Health 1 (2015) 40–43
TITLE: National Sleep Foundation’s sleep time duration recommendations: methodology and results summary
AUTHOR(S): Max Hirshkowitz, KaitlynWhiton, Steven M. Albert, Cathy Alessi,MD, Oliviero Bruni, Lydia DonCarlos, Nancy Hazen, John Herman, Eliot S. Katz, Leila Kheirandish-Gozal, David N. Neubauer, Anne E. O’Donnell, Maurice Ohayon, John Peever, Robert Rawding, Ramesh C. Sachdeva, Belinda Setters, Michael V. Vitiello, J. Catesby Ware, Paula J. Adams Hillard


Objective: The objective was to conduct a scientifically rigorous update to the National Sleep Foundation’s sleep duration recommendations.

Methods: The National Sleep Foundation convened an 18-member multidisciplinary expert panel, representing 12 stakeholder organizations, to evaluate scientific literature concerning sleep duration recommendations. We determined expert recommendations for sufficient sleep durations across the lifespan using the RAND/UCLA Appropriateness Method.

Results: The panel agreed that, for healthy individuals with normal sleep, the appropriate sleep duration for newborns is between 14 and 17 hours, infants between 12 and 15 hours, toddlers between 11 and 14 hours, preschoolers between 10 and 13 hours, and school-aged children between 9 and 11 hours. For teenagers, 8 to 10 hours was considered appropriate, 7 to 9 hours for young adults and adults, and 7 to 8 hours of sleep for older adults.

Conclusions: Sufficient sleep duration requirements vary across the lifespan and fromperson to person. The recommendations reported here represent guidelines for healthy individuals and those not suffering froma sleep disorder. Sleep durations outside the recommended range may be appropriate, but deviating far from the normal range is rare. Individuals who habitually sleep outside the normal range may be exhibiting signs or symptoms of serious health problems or, if done volitionally,may be compromising their health and well-being.




JOURNAL: J Sleep Res. (2014) 23, 143–152
TITLE: Insomnia and accidents: cross-sectional study (EQUINOX) on sleep-related home, work and car accidents in 5293 subjects with insomnia from 10 countries
AUTHOR(S): Damien Leger, Virginie Bayon, Maurice M. Ohayon, Pierre Philip, Philippe Ement, Arnaud Metlaine, Mounir Chennaoui, Brice Faraut


The link between sleepiness and the risk of motor vehicle accidents is well known, but little is understood regarding the risk of home, work and car accidents of subjects with insomnia. An international cross-sectional survey was conducted across 10 countries in a population of subjects with sleep disturbances. Primary care physicians administered a questionnaire that included assessment of sociodemographic characteristics, sleep disturbance and accidents (motor vehicle, work and home) related to sleep problems to each subject. Insomnia was defined using the International Classification of Sleep Disorders (ICSD-10) criteria. A total of 5293 subjects were included in the study, of whom 20.9% reported having had at least one home accident within the past 12 months, 10.1% at least one work accident, 9% reported having fallen asleep while driving at least once and 4.1% reported having had at least one car accident related to their sleepiness. All types of accident were reported more commonly by subjects living in urban compared to other residential areas. Car accidents were reported more commonly by employed subjects, whereas home injuries were reported more frequently by the unemployed. Car accidents were reported more frequently by males than by females, whereas home accidents were reported more commonly by females. Patients with insomnia have high rates of home accidents, car accidents and work accidents related to sleep disturbances independently of any adverse effects of hypnotic treatments. Reduced total sleep time may be one factor explaining the high risk of accidents in individuals who complain of insomnia.




JOURNAL: Sleep Medicine 15 (2014) 522–529
TITLE: The Burden of Narcolepsy Disease (BOND) study: health-care utilization and cost findings
AUTHOR(S): Jed Black, Nancy L. Reaven, Susan E. Funk, Karen McGaughey, Maurice Ohayon, Christian Guilleminault, Chad Ruoff , Emmanuel Mignot


Objectives: The aim of this study was to characterize health-care utilization, costs, and productivity in a large population of patients diagnosed with narcolepsy in the United States.

Methods: This retrospective, observational study using data from the Truven Health Analytics Market- Scan Research Databases assessed 5 years of claims data (2006–2010) to compare health-care utilization patterns, productivity, and associated costs among narcolepsy patients (identified by International Classification of Diseases, Ninth Revision (ICD9) narcolepsy diagnosis codes) versus matched controls. A total of 9312 narcolepsy patients (>18 years of age, continuously insured between 2006 and 2010) and 46,559 matched controls were identified.

Results: Compared with controls, narcolepsy subjects had approximately twofold higher annual rates of inpatient admissions (0.15 vs. 0.08), emergency department (ED) visits w/o admission (0.34 vs. 0.17), hospital outpatient (OP) visits (2.8 vs. 1.4), other OP services (7.0 vs. 3.2), and physician visits (11.1 vs. 5.6; all p < 0.0001). The rate of total annual drug transactions was doubled in narcolepsy versus controls (26.4 vs. 13.3; p < 0.0001), including a 337% and 72% higher usage rate of narcolepsy drugs and non-narcolepsy drugs, respectively (both p < 0.0001). Mean yearly costs were significantly higher in narcolepsy compared with controls for medical services ($8346 vs. $4147; p < 0.0001) and drugs ($3356 vs. $1114; p < 0.0001).

Conclusions: Narcolepsy was found to be associated with substantial personal and economic burdens, as indicated by significantly higher rates of health-care utilization and medical costs in this large US group of narcolepsy patients.




JOURNAL: Acad Psychiatry (2014) 38:655–660
TITLE: Moving Beyond Community Mental Health: Public Mental Health as an Emerging Focus for Psychiatry Residency Training
AUTHOR(S): Laura Weiss Roberts, Eugene V. Beresin, John H. Coverdale, Richard Balon, Alan K. Louie, Jane Paik Kim, Maurice M. Ohayon.


Mental disorders and behavioral conditions represent a challenge to the well-being of communities throughout the world. This statement is bold, certainly, but not without basis. One in four adults in the USA meets criteria for a mental disorder, and estimates from the World Health Organization indicate that mental disorders represent nearly 23 % of years lived with disability for all people globally [1, 2]. This level of disease burden is greater than that associated with HIV/AIDS, cancer, and diabetes combined. Moreover, themost common causes of death, including ischemic heart disease, stroke, chronic obstructive pulmonary disease, diabetes, HIV, and multiple forms of cancer, are linked with at-risk behaviors and behavioral conditions. The number of completed suicides each year— nearly 900,000 worldwide and 37,000 in the USA—in rough terms represents more than twice the number of people who die annually from war or from interpersonal violence.




JOURNAL: Journals of Gerontology, Series, B: Psychological Sciences and Social Sciences, 69(7), S35–S41
TITLE: Association Between Insomnia Symptoms and Functional Status in U.S. Older Adults
AUTHOR(S): Adam P. Spira, Christopher N. Kaufmann, Judith D. Kasper, Maurice M. Ohayon, George W. Rebok, Elizabeth Skidmore, Jeanine M. Parisi, and Charles F. Reynolds III


Objectives. We studied the association between insomnia symptoms and late-life functioning, including physical capacity, limitations in household activities, and participation in valued activities.

Methods. Participants were 6,050 adults independent in self-care activities from a representative sample of older Medicare beneficiaries. They completed objective measures of physical capacity and self-report measures of insomnia symptoms, help and difficulty with household activities, and participation in valued activities.

Results. After adjustment, insomnia symptoms were associated with a greater odds of receiving help or having difficulty with selected household activities (laundry, shopping), greater odds of help or difficulty with ≥1 household activity [1 symptom vs. 0, odds ratio (OR)=1.27, p < .05; 2 symptoms vs. 0, OR=1 .35, p < .01), and of restricted participation in specific valued activities (attending religious services, going out for enjoyment) and in ≥1 valued activity (1 symptom vs. 0, OR=1 .29, p < .05; 2 symptoms vs. 0, OR=1 .50, p < .01). There was no independent association between insomnia symptoms and physical capacity.

Discussion. Among older adults, insomnia symptoms are associated with a greater odds of limitation in household activities and of restricted participation in valued activities. Insomnia interventions may improve functioning and quality of life among elders.




JOURNAL: Journal of Psychosomatic Research 78 (2015) 52–57
TITLE: Challenging the validity of the association between oversleeping and overeating in atypical depression
AUTHOR(S): Ohayon MM., O'Hara R., Vitiello MV.


Objective: In this study,we used a strict definition of hypersomnia and tested if the association between overeating– hypersomnia remained positive and significant. Hypersomnia was present if the total sleep time was close to 10 h per day or was at least 2 h longer than in normothymic periods.

Methods: Cross-sectional study using the adult general population of California and New York. The sample was composed of 6694 individuals aged between 18 and 96 years. Participants were interviewed by telephone using the Sleep-EVAL system. The interviews included various sleep and health topics and the assessment of DSM-IV sleep and psychiatric disorders.

Results: The one-month prevalence of major depressive episode was 6.1%, including a one-month prevalence of atypical depression of 1.6%, in this sample. Atypical depression subjects had a greater number of depressive symptoms and a longer duration of the current depressive episode than the other depressive subjects. Depressive subjects with hypersomnia slept longer (8 h, 29 min) than the other depressive subjects (6 h, 36 min) and longer than the subjects “getting too much sleep” (6 h, 48 min). Furthermore, hypersomnia was not associated with overeating while “getting too much sleep” showed a positive association with overeating.

Conclusions: Hypersomnia needs to be evaluated using a strict definition. Otherwise, it leads to an overestimation of this symptom in major depressive episode subjects and to a false association with overeating.




JOURNAL: Neurology 2014;83;834-841
TITLE: Are confusional arousals pathological?
AUTHOR(S): Maurice M. Ohayon, Mark W. Mahowald and Damien Leger


Objective: The objective of this study was to determine the extent that confusional arousals (CAs) are associated with mental disorders and psychotropic medications.

Methods: Cross-sectional study conducted with a representative sample of 19,136 noninstitutionalized individuals of the US general population aged 18 years or older. The study was performed using the Sleep-EVAL expert system and investigated sleeping habits; health; and sleep, mental, and medical conditions (DSM-IV-TR, ICSD-II, ICD-10).

Results: A total of 15.2% (95% confidence interval 14.6%–15.8%) (n 5 2,421) of the sample reported episodes of CAs in the previous year; 8.6% had complete or partial amnesia of the episodes and 14.8% had CAs and nocturnal wandering episodes. Eighty-four percent of CAs were associated with sleep/mental disorders or psychotropic drugs. Sleep disorders were present for 70.8% of CAs. Individuals with a circadian rhythm sleep disorder or a long sleep duration ($9 hours) were at higher risk of CAs. Mental disorders were observed in 37.4% of CAs. The highest odds were observed in individuals with bipolar disorders or panic disorder. Use of psychotropic medication was reported by 31.3% of CAs: mainly antidepressant medications. After eliminating possible causes and associated conditions, only 0.9% of the sample had CA disorder.

Conclusions: CAs are highly prevalent in the general population. They are often reported allegedly as a consequence of the treatment of sleep disorders. For the majority of subjects experiencing CAs, no medications were used, but among those who were using medications, antidepressants were most common. Sleep and/or mental disorders were important factors for CAs independent of the use of any medication.




JOURNAL: Journal of Psychiatric Research xxx (2014) 1-6
TITLE: Chronic Obstructive Pulmonary Disease and its association with sleep and mental disorders in the general population
AUTHOR(S): Maurice M. Ohayon


Objective: To assess the prevalence of insomnia symptoms in Chronic Obstructive Pulmonary Disease (COPD) participants, their association with psychiatric disorders and their impact on health care utilization and quality of life.

Method: It is a cross-sectional telephone study using a representative sample consisting of 10,854 noninstitutionalized individuals aged 15 or over living in Germany, Spain and the United Kingdom. Interviews were managed by the Sleep-EVAL expert system. The questionnaire included questions on sleeping habits, life habits, health, DSM-IV mental disorders, DSM-IV and ICSD sleep disorders. COPD was defined as chronic bronchitis or emphysema (treated or not) diagnosed by a physician.

Results: A total of 2.5% [2.1%e2.8%] of the sample reported having been diagnosed with COPD. As many as 48.1% of COPD had insomnia symptoms, which was twice higher than the rate observed in non-COPD (OR: 2.4). Only 11.8% of COPD addressed their sleep difficulties to their physician.Mental disorders were higher in COPD compared to non-COPD participants: Major Depressive disorder (AOR: 2.8); Generalized Anxiety Disorder (AOR: 11.0); Panic Disorder (AOR: 7.1) and Specific Phobia (AOR: 3.7). As many as 84.4% of COPD with depression and 59.7% of those with an Anxiety Disorder had associated insomnia symptoms. The cooccurrence of both conditions increased by five times the likelihood of hospitalizations in the previous year among COPD. Both conditions were associated with a diminished Quality of Life in COPD.

Conclusions: COPD is a debilitating disease accompanied with psychiatric disorders and sleep disturbances in the overwhelming majority of cases. This high comorbidity is associated with greater health care utilization and great deterioration of the quality of life.




JOURNAL: Journal of Psychiatric Research 49 (2014) 10-17
TITLE: Links between occupational activities and depressive mood in young adult populations
AUTHOR(S): Maurice M. Ohayon, Laura Weiss Roberts


Background: To examine how occupational activities (work, school), separation from parents, environmental conditions, stressors ad social insertion affect on the prevalence of Major Depressive Disorder (MDD) and mental health care-seeking among young adults.

Methods: Cross-sectional study conducted in two samples: 1) 19,136 subjective representative of the US non-institutionalized general population including 2082 18e26 y.o. subjects. 2) 2196 subjects representative of the students’ population living on an university campus. Telephone interviews were realized using the Sleep-EVAL system to assess sleeping habits, general health, organic, sleep and mental disorders.

Results: One-month prevalence of depressed mood was similar between community and campus student groups (21.7% and 23.4%), and less common than for working (23.6%) and non-working (28.2%) young adults in the community. One-month MDD was found in 12.0% of non-working young people, compared with 6.6% of young workers, 3.2% of on-campus students and 4.1% of students in the general population (p < 0.01). Correlates for depressive mood and MDD such as female gender, dissatisfaction with social life, obesity, living with pain and other factors were identified across groups. A minority of on-campus (10.8%) and general population students (10.3%) had sought mental health services in the prior year. Individuals with MDD had higher rates of care-seeking than other young people (p < 0.001), high rates of psychotropic medication use (p < 0.001).

Conclusions: Being a student appears to have a protective effect with respect to having depressive symptoms or MDD and seeking needed mental health care. Stress and social isolation were important determinants for depression among young adults.




JOURNAL: Annals of Neurology Vol 74 (suppl 17) 2013
TITLE: Narcolepsy and Comorbid Psychiatric and Medical Conditions
AUTHOR(S): Maurice M. Ohayon, Jed Black.


Understanding comorbid conditions associated with narcolepsy is of utmost importance when devising an appropriate treatment. This study aims to examine psychiatric disorders and medical conditions associated with Narcolepsy. For this study, 320 narcoleptic individuals were interviewed sleeping habits; health; medication consumption, medical conditions (ICD-10), sleep disorders (ICSD) and mental disorders (DSM-IV-TR) using Sleep-EVAL. A general population comparison group (N51464), matched for age, sex and BMI and interviewed with the same instrument, was used to estimate odds ratios. Compared to the general population, narcoleptic individuals were more likely to have psychiatric disorders; Major Depressive Disorder (MDD) (OR:2.67) and Social Anxiety Disorder (SAD) (OR:2.43) affecting each nearly 20% of narcoleptic individuals. MDD mostly developed after the onset of narcolepsy (88%) while SAD was present before the onset of narcolepsy in half of the cases. Among medical conditions, hypercholesterolaemia (OR:1.51); Diseases of the digestive system (OR:3.27); Heart diseases (OR:2.07); Upper respiratory tract diseases (OR:2.52) and Hypertension (OR:1.32) were more frequently reported in the narcolepsy group. The high medical and psychiatric comorbidity found in this study underlines the risk of leaving undiagnosed or misdiagnosed individuals, which need to be addressed when developing a treatment plan.

Study supported by: NIH (R01NS044199) and unrestricted educational grant from Jazz Pharmaceuticals.




JOURNAL: Annals of Neurology Vol 74 (suppl 17) 2013
TITLE: Sex-Related Differences in Narcolepsy Burden of Illness: Burden of Narcolepsy Disease (BOND) Database Analysis
AUTHOR(S): Jed Black, Nancy Reaven, Susan Funk, Karen McGaughey, Maurice Ohayon, Christian Guilleminault, Chad Ruoff


No large database analyses of sex-related patterns of narcolepsy burden of illness have been reported. Truven Health Analytics MarketScanVR Databases (>50 million covered lives) were accessed to identify individuals !18 years of age with narcolepsy 1 cataplexy continuously insured between 2006 and 2010 (n59,312; 59.2% female); controls without narcolepsy were matched 5:1 on multiple factors (n546,559). Rates of healthcare service utilization were significantly higher among narcolepsy patients compared to controls, regardless of sex (males, 17.6 vs 8.5 services/pt/yr; females, 24.0 vs 11.8 services/pt/yr; P <0.0001), as were the mean number of annual drug transactions (males, 22.3 vs 11.5; females, 29.3 vs 14.5; P<0.0001). Costs and drug utilization followed a similar pattern. Utilization of services was higher in female vs. male patients in both narcolepsy (36.4% excess) and control (38.8% excess) cohorts. Both male and female narcolepsy patients had a significantly greater number of comorbid diagnoses compared with controls, including many not previously associated with narcolepsy. Odds ratios for almost all comorbidity categories were higher in females vs. males; this finding was even more pronounced within the narcolepsy cohort, with the exceptions of obstetrics/fertility and perinatal categories.

Study supported by: Jazz Pharmaceuticals; J Black has served as a paid consultant for Jazz Pharmaceuticals, and is employed part time by Jazz Pharmaceuticals.




JOURNAL: Sleep Medicine 13 (2012) 52–57
TITLE: Hierarchy of insomnia criteria based on daytime consequences
AUTHOR(S): Maurice M. Ohayon, Dieter Riemann, Charles Morin, Charles F. Reynolds III


Objectives: To explore how insomnia symptoms are hierarchically organized in individuals reporting daytime consequences of their sleep disturbances.

Methods: This is a cross-sectional study conducted in the general population of the states of California, New York, and Texas. The sample included 8937 individuals aged 18 years or older representative of the general population. Telephone interviews on sleep habits and disorders were managed with the Sleep-EVAL expert system and using DSM-IV and ICSD classifications. Insomnia symptoms and global sleep dissatisfaction (GSD) had to occur at least three times per week for at least three months.

Results: A total of 26.2% of the sample had a GSD. Individuals with GSD reported at least one insomnia symptom in 73.1% of the cases. The presence of GSD in addition to insomnia symptoms considerably increased the proportion of individuals with daytime consequences related to insomnia. In the classification trees performed, GSD arrived as the first predictor for daytime consequences related to insomnia. The second predictor was nonrestorative sleep followed by difficulty resuming sleep and difficulty initiating sleep.

Conclusions: Classification trees are a useful way to hierarchically organize symptoms and to help diagnostic classifications. In this study, GSD was found to be the foremost symptom in identifying individuals with daytime consequences related to insomnia.




JOURNAL: Program and Abstracts, American Neurological Association
TITLE: A Longitudinal Study of 322 Individuals with Narcolepsy
AUTHOR(S): Maurice M. Ohayon


Objectives: Many progresses have been done in understanding the genetic basis of Narcolepsy. However, little is known about the evolution of narcoleptic individuals in terms of mortality and comorbidity.

Methods: A total of 322 narcoleptic individuals interviewed at first time between 2005 and 2007 were contacted again between October 2011 and January 2012. The success rate in contacting the initial sample was 95.65%. As with the initial interview, during the followup, the interview covered sleep, mental and organic diseases. Initial and follow-up interviews were performed using the Sleep-EVAL system.

Results: Of the 308 narcoleptic individuals located, 4 refused to participate, 1 was unavailable for other reasons, 5 were too ill and 7 were deceased. At follow-up, subjects were aged between 21 and 84 years. The most frequently reported new disease was hypertension (3.1%) followed by diabetes (2.6%) and cancer (2.2%). Overall death rate was comparable between narcoleptic sample and the U.S. general population for the same time period. However, suicide rate was seven times higher in the narcoleptic sample (RR:7.35 [1.84-29.41]).

Conclusion: Narcolepsy is accompanied by various medical conditions but also mental disorders, which place narcoleptic individuals at greater risk for suicide. Study supported by: NIH (R01NS044199) and unrestricted educational grant from Jazz Pharmaceuticals




JOURNAL: Program and Abstracts, American Neurological Association
TITLE: Medical Conditions and Psychiatric Disorders Associated with Narcolepsy
AUTHOR(S): Maurice M. Ohayon


Objectives: Individuals affected by Narcolepsy represent a vulnerable segment of the population. We have, however, only a partial understanding of this vulnerability. This study aims to examine psychiatric disorders and medical conditions associated with Narcolepsy.

Methods: A total of 320 narcoleptic individuals were interviewed sleeping habits; health; medication consumption, medical conditions (ICD-10), sleep disorders (ICSD) and mental disorders (DSM-IV-TR) using the Sleep- EVAL. system A general population comparison group (N ¼ 1,464), matched for age, sex and BMI and interviewed with the same instrument, was used to estimate odds ratios.

Results: Five diseases were more frequently observed among narcoleptic individuals: Hypercholesterolaemia (OR: 1.51); Diseases of the digestive system (OR: 3.27); Heart diseases (OR: 2.07); Upper respiratory tract diseases (OR: 2.52) and Hypertension (OR: 1.32). Most frequent psychiatric disorders among the narcolepsy group were Major Depressive Disorder (OR: 2.67) and Social Anxiety Disorder (OR: 2.43) both affecting nearly 20% of narcoleptic individuals. However, most mood and anxiety disorders were more prevalent among narcoleptic group. Alcohol Abuse/Dependence was comparable between groups.

Conclusions: Narcolepsy is associated with a high comorbidity of both medical conditions and psychiatric disorders that need to be addressed when developing a treatment plan.

Study supported by: NIH (R01NS044199) and unrestricted educational grant from Jazz Pharmaceuticals




JOURNAL: ANN NEUROL 2013;73:785–794
TITLE: Excessive Sleep Duration and Quality of Life
AUTHOR(S): Maurice M. Ohayon, Charles F. Reynolds, III, and Yves Dauvilliers


Objective: Using population-based data, we document the comorbidities (medical, neurologic, and psychiatric) and consequences for daily functioning of excessive quantity of sleep (EQS), defined as a main sleep period or 24-hour sleep duration !9 hours accompanied by complaints of impaired functioning or distress due to excessive sleep, and its links to excessive sleepiness.

Methods: A cross-sectional telephone study using a representative sample of 19,136 noninstitutionalized individuals living in the United States, aged !18 years (participation rate ¼ 83.2%). The Sleep-EVAL expert system administered questions on life and sleeping habits; health; and sleep, mental, and organic disorders (Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision; International Classification of Sleep Disorders: Diagnostic and Coding Manual II, International Classification of Diseases and Related Health Problems, 10th edition).

Results: Sleeping at least 9 hours per 24-hour period was reported by 8.4% (95% confidence interval ¼ 8.0–8.8%) of participants; EQS (prolonged sleep episode with distress/impairment) was observed in 1.6% (1.4–1.8%) of the sample. The likelihood of EQS was 3 to 12# higher among individuals with a mood disorder. EQS individuals were 2 to 4# more likely to report poor quality of life than non-EQS individuals as well as interference with socioprofessional activities and relationships. Although between 33 and 66% of individuals with prolonged sleep perceived it as a major problem, only 6.3 to 27.5% of them reported having sought medical attention.

Interpretation: EQS is widespread in the general population, co-occurring with a broad spectrum of sleep, medical, neurologic, and psychiatric disorders. Therefore, physicians must recognize EQS as a mixed clinical entity indicating careful assessment and specific treatment planning.




JOURNAL: Journalof Psychiatric Research (2012)
TITLE: Prevalence and comorbidity of chronic pain in the German general population
AUTHOR(S): Maurice M. Ohayon, Julia C. Stingl


The objectives of this study were to evaluate 1) the prevalence of chronic and neuropathic pain features (NeP); 2) their comorbidities with psychiatric disorders and organic diseases; and 3) their impact on daily life and health care utilization. A random sample of 3011 participants (!15 years), representative of Germany, was interviewed by telephone. Chronic pain duration was set at three months. Neuropathy, frequency, severity, duration, impacts on functioning, and health care utilizations were investigated. Psychiatric disorders were assessed using DSM-IV-TR criteria. ICD-10 was used for organic diseases. Overall, 26.8% (95% confidence interval: 25.2e28.4%) of the sample reported having pain; 1.9% had acute pain (i.e., lasting less than three months), setting the prevalence of chronic pain at 24.9%. More precisely, 18.4% of the sample had non-neuropathic chronic pain (non-NeP) and 6.5% had NeP features. NeP presented several differences from non-NeP: individuals NeP features reported higher pain severity and higher interference of pain in daily activities compared to the non-NeP group. Individuals suffering from a major depressive disorder were three times more likely to have non-NeP and six times more likely to have NeP features. Individuals with obesity, diabetes, hypertension, cerebrovascular diseases, diseases of the nervous system, and diseases of the blood and blood-forming organs were at higher risk of having NeP but not non-NeP. These differences in prevalence and comorbidities between non-NeP and NeP features show how important it is to regard these different modalities of pain separately. Participants with NeP features suffer more and have greater impairment in their daily life than those with non-NeP




JOURNAL: Accident Analysis and Prevention
TITLE: Sleep disorders, medical conditions, and road accident risk
AUTHOR(S): Michael H. Smolensky, Lee Di Milia, Maurice M. Ohayon, Pierre Philip


Sleep disorders and various common acute and chronic medical conditions directly or indirectly affect the quality and quantity of one’s sleep or otherwise cause excessive daytime fatigue. This article reviews the potential contribution of several prevalent medical conditions – allergic rhinitis, asthma, chronic obstructive pulmonary disease, rheumatoid arthritis/osteoarthritis – and chronic fatigue syndrome and clinical sleep disorders – insomnia, obstructive sleep apnea, narcolepsy, periodic limb movement of sleep, and restless legs syndrome – to the risk for drowsy-driving road crashes. It also explores the literature on the cost-benefit of preventive interventions, using obstructive sleep apnea as an example. Although numerous investigations have addressed the impact of sleep and medical disorders on quality of life, few have specifically addressed their potential deleterious effect on driving performance and road incidents. Moreover, since past studies have focused on the survivors of driver crashes, they may be biased. Representative population-based prospective multidisciplinary studies are urgently required to clarify the role of the fatigue associated with common ailments and medications on traffic crash risk of both commercial and non-commercial drivers and to comprehensively assess the cost-effectiveness of intervention strategies.




JOURNAL: Academic Psychiatry, 37:5, September-October 2013
TITLE: Strengthening Psychiatry’s Numbers
AUTHOR(S): Laura Weiss Roberts, Maurice Ohayon, John Coverdale, Michelle Goldsmith, Eugene V. Beresin, Alan K. Louie, Glendon R. Tait, Richard Balon


A total of 681 students graduating from allopathic medical schools in the United States matched into psychiatry residencies in 2013 (1). This number, small as it is, represents an increase in the percentage of U.S. medical student seniors entering psychiatry. Last year, only 3.9% of U.S. seniors—616 men and women—matched in psychiatry programs as PGY-1 residents, whereas, this year, the figure rose a tad to 4.2% (1). When compared with the ever-increasing numbers of people living in the U.S., that is, the base population of individuals who may be affected by neuropsychiatric diseases and behavioral conditions, this slight increase does not nearly keep pace (Table 1). Also, the number of U.S. medical students matching into psychiatry presents only a part of the whole picture: 681 U.S. medical students filled just about half of the positions offered in the 2013 match (1,360 positions offered; 1,330 filled); the remaining positions were filled with international medical graduates (U.S. and non-U.S. citizens), Canadian medical students, graduates from osteopathic schools, and students who graduated the previous year. Moreover, of the nearly three-quarters-of-a-million active physicians in the United States, psychiatry is third only to preventive medicine and clinical pathology as the specialty with the most physicians who are age 55 years or older (2). In sum, psychiatry is among the lowest specialties in terms of overall growth.




JOURNAL: Dauvilliers et al. BMC Medicine 2013, 11:78
TITLE: Hypersomnia and depressive symptoms: methodological and clinical aspects
AUTHOR(S): Yves Dauvilliers, Régis Lopez, Maurice Ohayon and Sophie Bayard


The associations between depressive symptoms and hypersomnia are complex and often bidirectional. Of the many disorders associated with excessive sleepiness in the general population, the most frequent are mental health disorders, particularly depression. However, most mood disorder studies addressing hypersomnia have assessed daytime sleepiness using a single response, neglecting critical and clinically relevant information about symptom severity, duration and nighttime sleep quality. Only a few studies have used objective tools such as polysomnography to directly measure both daytime and nighttime sleep propensity in depression with normal mean sleep latency and sleep duration. Hypersomnia in mood disorders, rather than a medical condition per se, is more a subjective sleep complaint than an objective finding. Mood symptoms have also been frequently reported in hypersomnia disorders of central origin, especially in narcolepsy. Hypocretin deficiency could be a contributing factor in this condition. Further interventional studies are needed to explore whether management of sleep complaints improves mood symptoms in hypersomnia disorders and, conversely, whether management of mood complaints improves sleep symptoms in mood disorders.




JOURNAL: Sleep Med (2013)
TITLE: Narcolepsy is complicated by high medical and psychiatric comorbidities: a comparison with the general population
AUTHOR(S): Maurice M. Ohayon


Background: Individuals affected with narcolepsy represent a vulnerable segment of the population. However, we only have a partial understanding of this vulnerability. Our study aims to examine psychiatric disorders and medical conditions associated with narcolepsy.

Methods: A total of 320 narcoleptic participants were interviewed regarding sleeping habits, health, medication consumption, medical conditions (International Statistical Classification of Diseases and Related Health Problems, 10th edition), sleep disorders (International Classification of Sleep Disorders, second edition [ICSD-2]) and mental disorders (Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision [DSM-IV-TR]) using Sleep-EVAL. A general population comparison sample (N = 1464) matched for age, sex, and body mass index (BMI) and interviewed with the same instrument was used to estimate odds ratios (OR).

Results: Five diseases were more frequently observed among narcoleptic participants, including hypercholesterolemia (OR, 1.51), diseases of the digestive system (OR, 3.27), heart diseases (OR, 2.07), upper respiratory tract diseases (OR, 2.52), and hypertension (OR, 1.32). Most frequent psychiatric disorders among the narcolepsy group were major depressive disorder (MDD) (OR, 2.67) and social anxiety disorder (OR, 2.43), both affecting nearly 20% of narcoleptic individuals. However, most mood and anxiety disorders were more prevalent among the narcoleptic group. Alcohol abuse or alcohol dependence was comparable between groups.

Conclusions: Narcolepsy is associated with a high comorbidity of both medical conditions and psychiatric disorders that need to be addressed when developing a treatment plan.




JOURNAL: Journal of Psychiatric Research (2013)
TITLE: Associations between morningness/eveningness and psychopathology: An epidemiological survey in three in-patient psychiatric clinics
AUTHOR(S): Patrick Lemoine, Philippe Zawieja, Maurice M. Ohayon


Objective: This study aims to examine the association between the chronotype (morningness/eveningness) and specific mental disorders.

Methods: Cross-sectional epidemiological study conducted in three in-patient clinical settings. A total of 1468 consecutive in-patients who gave their written consent were enrolled. On the admission day, patients filled sleep questionnaires and a nurse filled a Clinical Global Impressions scale. Hospitalization reports and ICD-10 diagnoses were collected.

Results: Sleep/wake schedule was similar between the psychiatric diagnoses. On the other hand, morning type patients had an earlier bedtime, earlier wakeup time and shorter sleep duration than the other chronotype regardless of the diagnosis. In multivariate models, patients with a depressive disorder or a psychosis were more likely to be morning type. Patients with an anxiety disorder, addiction disorder or personality disorder were more likely to be evening type.

Conclusions: Age and sleep/wake schedule are contributing factors for the chronotype but mental disorders too appeared to modulate chronotype preferences




JOURNAL: Neurology 2012;78;1583
TITLE: Prevalence and comorbidity of nocturnal wandering in the US adult general population
AUTHOR(S): M.M. Ohayon, M.W. Mahowald, Y. Dauvilliers, et al.


Objective: To assess the prevalence and comorbid conditions of nocturnal wandering with abnormal state of consciousness (NW) in the American general population.

Methods: Cross-sectional study conducted with a representative sample of 19,136 noninstitutionalized individuals of the US general population 18 years old. The Sleep-EVAL expert system administered questions on life and sleeping habits; health; and sleep, mental, and organic disorders (DSM-IV-TR; International Classification of Sleep Disorders, version 2; International Classification of Diseases–10).

Results: Lifetime prevalence of NW was 29.2% (95% confidence interval [CI] 28.5%–29.9%). In the previous year, NW was reported by 3.6% (3.3%–3.9%) of the sample: 1% had 2 or more episodes per month and 2.6% had between 1 and 12 episodes in the previous year. Family history of NW was reported by 30.5% of NW participants. Individuals with obstructive sleep apnea syndrome (odds ratio [OR] 3.9), circadian rhythm sleep disorder (OR 3.4), insomnia disorder (OR 2.1), alcohol abuse/dependence (OR 3.5), major depressive disorder (MDD) (OR 3.5), obsessivecompulsive disorder (OCD) (OR 3.9), or using over-the-counter sleeping pills (OR 2.5) or selective serotonin reuptake inhibitor (SSRI) antidepressants (OR 3.0) were at higher risk of frequent NW episodes (2 times/month).

Conclusions: With a rate of 29.2%, lifetime prevalence ofNWis high. SSRIs were associated with an increased risk of NW. However, these medications appear to precipitate events in individuals with a prior history of NW. Furthermore, MDD and OCD were associated with significantly greater risk of NW, and this was not due to the use of psychotropic medication. These psychiatric associations imply an increased risk due to sleep disturbance. Neurology® 2012;78:1583–1589




JOURNAL: Journal of Psychiatric Research
TITLE: Determining the level of sleepiness in the American population and its correlates
AUTHOR(S): Maurice M. Ohayon


Objective: To assess the prevalence, to determine the risk factors and to evaluate the impacts of excessive sleepiness in the general population. Method: It is a cross-sectional telephone study using a representative sample consisting of 8937 noninstitutionalized individuals aged 18 or over living in Texas, New York and California. They represented a total of 62.8 million inhabitants. The participation rate was 85.6% in California, 81.3% in New York and 83.2% in Texas. Interviews were managed by the Sleep-EVAL expert system. The questionnaire included questions on sleeping habits, life habits, health, DSM-IV mental disorders, DSM-IV and ICSD sleep disorders.

Results: As many as 19.5% of the sample reported having moderate excessive sleepiness and 11.0% reported severe excessive sleepiness. Moderate excessive sleepiness was comparable between men and women but severe excessive sleepiness was higher in women (8.6% vs. 13.0%). Factors associated with moderate excessive sleepiness were sleeping 6 h or less per main sleep episode (OR:2.0); OSAS (OR:2.0); insomnia disorder (OR:2.4); Restless Legs Syndrome (OR: 1.8) major depressive disorder (OR: 1.7); anxiety disorder (OR:1.5) and use of tricyclic antidepressant (OR: 2.1) presence of heart disease (OR: 1.5), cancer (1.8) and chronic pain (1.3). Factors associated with severe excessive sleepiness were similar with the addition of being a woman (OR:1.5), alcohol dependence (OR: 1.4), bipolar disorder (OR: 2.1), use of over-the-counter sleeping pills (OR: 2.5), narcotic analgesics (OR: 3.4), Antidepressants (other than SSRI or tricyclic) and presence of gastro-esophageal reflux disease (OR:1.6). Sleepy individuals were twice as likely than non-sleepy participants to have had accidents while they were at the wheel of a vehicle during the previous year.

Conclusions: Excessive sleepiness is highly prevalent in the American population. It was strongly associated with insufficient sleep and various sleep disorders as well as mental and organic diseases.




JOURNAL: ARCH GEN PSYCHIATRY/VOL 69 (NO. 1), JAN 2012
TITLE: Operational Definitions and Algorithms for Excessive Sleepiness in the General Population
AUTHOR(S): Ohayon MM., O'Hara R., Vitiello MV.


Context: Excessive sleepiness (ES) is poorly defined in epidemiologic studies, although its adverse implications for safety, health, and optimal social and vocational functioning have been extensively reported.

Objective: To determine the importance of ES definition, measurement, and prevalence in the general population, together with its coexisting conditions.

Design: Cross-sectional telephone study. Participants: A total of 15 929 individuals representative of the adult general population of 15 states in the United States.

Main Outcome Measures: Interviews were carried out using Sleep-EVAL, a knowledge-based expert system for use in epidemiologic studies, focusing on sleep, as well as physical and mental disorders, according to classification in DSM-IV and the second edition of the International Classification of Sleep Disorders. The interviews elicited information on ES, naps, frequency, duration, impairment, and distress associated with ES symptoms.




JOURNAL: Sleep Medicine Reviews
TITLE: Epidemiology of restless legs syndrome: A synthesis of the literature
AUTHOR(S): Maurice M. Ohayon, Ruth O’Hara, Michael V. Vitiello


Restless legs syndrome (RLS) has gained considerable attention in the recent years: nearly 50 community-based studies have been published in the last decade around the world. The development of strict diagnostic criteria in 1995 and their revision in 2003 helped to stimulate research interest on this syndrome. In community-based surveys, RLS has been studied as: 1) a symptom only, 2) a set of symptoms meeting minimal diagnostic criteria of the international restless legs syndrome study group (IRLSSG), 3) meeting minimal criteria accompanied with a specific frequency and/or severity, and 4) a differential diagnosis. In the first case, prevalence estimates in the general adult population ranged from 9.4% to 15%. In the second case, prevalence ranged from 3.9% to 14.3%. When frequency/severity is added, prevalence ranged from 2.2% to 7.9% and when differential diagnosis is applied prevalence estimates are between 1.9% and 4.6%. In all instances, RLS prevalence is higher in women than in men. It also increases with age in European and North American countries but not in Asian countries. Symptoms of anxiety and depression have been consistently associated with RLS. Overall, individuals with RLS have a poorer health than non-RLS but evidence for specific disease associations is mixed. Future epidemiological studies should focus on systematically adding frequency and severity in the definition of the syndrome in order to minimize the inclusion of cases mimicking RLS.




JOURNAL: Sleep Med Res 2011;2:1-9
TITLE: Epidemiological Overview of Sleep Disorders in the General Population
AUTHOR(S): Ohayon MM.


There are several hundred of epidemiological studies assessing different sleep complaints and disorders in the general population. This article summarizes the main findings of these studies and underlines some of the aspects that still need to be investigated. Insomnia complaint is one of the most studied sleep disturbances. Nearly one third of the general population complains of insomnia but a diagnosis is warranted in only 6% to 15% of the population. Excessive sleepiness is also another frequent complaint. However, its definition and method of assessment are so diverse that it is difficult to have a clear estimate of its prevalence in the general population: prevalence rates are ranging between 4% and 26%. Narcolepsy is a rare disorder with a prevalence averaging 0.04% in the general population. Obstructive Sleep Apnea Syndrome, often associated with insomnia or excessive sleepiness, is found in approximately 2% to 4% of the general population and has a higher prevalence in men than in women. Restless legs syndrome (RLS), depending on how it was assessed, varies from a low 1% in Asian countries to a high 19% in Northern European countries. RLS is higher in women and increases with age. Unfortunately, despite the high prevalence, sleep disorders remain poorly identified; less than 20% of individuals with insomnia are correctly diagnosed and treated. The figures are even lower for excessive sleepiness and RLS with less than 10% correctly diagnosed and treated.




JOURNAL: Sleep Med Rev. 2011 Jul 25. [Epub ahead of print]
TITLE: Epidemiology of restless legs syndrome: A synthesis of the literature.
AUTHOR(S): Ohayon MM., O'Hara R., Vitiello MV.


Restless legs syndrome (RLS) has gained considerable attention in the recent years: nearly 50 community-based studies have been published in the last decade around the world. The development of strict diagnostic criteria in 1995 and their revision in 2003 helped to stimulate research interest on this syndrome.

In community-based surveys, RLS has been studied as:
1) a symptom only,
2) a set of symptoms meeting minimal diagnostic criteria of the international restless legs syndrome study group (IRLSSG),
3) meeting minimal criteria accompanied with a specific frequency and/or severity, and
4) a differential diagnosis.

- In the first case, prevalence estimates in the general adult population ranged from 9.4% to 15%.
- In the second case, prevalence ranged from 3.9% to 14.3%.

When frequency/severity is added, prevalence ranged from 2.2% to 7.9% and when differential diagnosis is applied prevalence estimates are between 1.9% and 4.6%. In all instances, RLS prevalence is higher in women than in men. It also increases with age in European and North American countries but not in Asian countries. Symptoms of anxiety and depression have been consistently associated with RLS. Overall, individuals with RLS have a poorer health than non-RLS but evidence for specific disease associations is mixed. Future epidemiological studies should focus on systematically adding frequency and severity in the definition of the syndrome in order to minimize the inclusion of cases mimicking RLS.




JOURNAL: Nat Genet. 2011 Jan;43(1):66-71. Epub 2010 Dec 19.
TITLE: Common variants in P2RY11 are associated with narcolepsy.
AUTHOR(S): Kornum BR, Kawashima M, Faraco J, Lin L, Rico TJ, Hesselson S, Axtell RC, Kuipers H, Weiner K, Hamacher A, Kassack MU, Han F, Knudsen S, Li J, Dong X, Winkelmann J, Plazzi G, Nevsimalova S, Hong SC, Honda Y, Honda M, Hogl B, Ton TG, Montplaisir J, Bourgin P, Kemlink D, Huang YS, Warby S, Einen M, Eshragh JL, Miyagawa T, Desautels A, Ruppert E, Hesla PE, Poli F, Pizza F, Frauscher B, Jeong JH, Lee SP, Strohl KP, Longstreth WT Jr, Kvale M, Dobrovolna M, Ohayon MM, Nepom GT, Wichmann HE, Rouleau GA, Gieger C, Levinson DF, Gejman PV, Meitinger T, Peppard P, Young T, Jennum P, Steinman L, Tokunaga K, Kwok PY, Risch N, Hallmayer J, Mignot E.


Growing evidence supports the hypothesis that narcolepsy with cataplexy is an autoimmune disease.

We here report genome-wide association analyses for narcolepsy with replication and fine mapping across three ethnic groups (3,406 individuals of European ancestry, 2,414 Asians and 302 African Americans). We identify a SNP in the 3' untranslated region of P2RY11, the purinergic receptor subtype P2Y11 gene, which is associated with narcolepsy (rs2305795, odds ratio = 1.28, 95% CI 1.19-1.39, n = 5689). The disease-associated allele is correlated with reduced expression of P2RY11 in CD8(+) T lymphocytes (339% reduced, P = 0.003) and natural killer (NK) cells (P = 0.031), but not in other peripheral blood mononuclear cell types. The low expression variant is also associated with reduced P2RY11-mediated resistance to ATP-induced cell death in T lymphocytes (P = 0.0007) and natural killer cells (P = 0.001).

These results identify P2RY11 as an important regulator of immune-cell survival, with possible implications in narcolepsy and other autoimmune diseases.




JOURNAL: J Psychosom Res. 2010 Dec;69(6):565-71.
TITLE: Nocturnal awakenings and difficulty resuming sleep: Their burden in the European general population.
AUTHOR(S): Ohayon MM.


OBJECTIVES: To (1) define the prevalence and importance of nocturnal awakenings (NA) in the general population, and (2) investigate its associations with daytime impairment, physical diseases, and psychiatric disorders.

METHODS: This is a cross-sectional telephone study conducted in the general population of France, United Kingdom, Germany, Italy, and Spain. A representative sample consisting of 22,740 non-institutionalized individuals aged 15 or over was interviewed regarding sleeping habits, health, sleep and mental disorders. Nocturnal awakenings were evaluated according to their frequency per week and per night and their duration.

RESULTS: At the time of the interview, 31.2% (95% confidence interval: 30.6-31.8%) of the sample reported waking up at least 3 nights per week and 7.7% (7.4% to 8.0%) of the sample had difficulty resuming sleep (DRS) after they woke up. Duration of the symptom was longer than one year in 78.8% of the cases. DRS had greater impacts on daytime functioning than any other kind of NA or other insomnia symptoms with odds ratios five to seven times higher than individuals waking up once or twice within the same night. Individuals with painful physical condition or with a psychiatric disorder were more than four times more likely to have DRS. Other significant factors associated with NA were hypertension, cardio-vascular disease, upper airway disease, diabetes, and heavy caffeine consumption.

CONCLUSIONS: Nocturnal awakenings are highly prevalent in the general population and strongly associated with various physical diseases and psychiatric disorders. There is also a dose response effect in the associations: odds ratios increased with the number of awakenings during the same night and the difficulty resuming sleep once awakened. The study shows that nocturnal awakenings are complex and should be assessed systematically.




JOURNAL: Sleep Med. 2010 Dec;11(10):1010-8.
TITLE: Prevalence of insomnia and sleep characteristics in the general population of Spain.
AUTHOR(S): Ohayon MM, Sagales T.


OBJECTIVE: The goals of this study were to estimate the prevalence of insomnia symptomatology and diagnoses in the Spanish general population and to determine if certain sleep parameters were related to specific insomnia symptoms.

METHODS: This is a cross-sectional telephone survey performed in the general population of Spain using a representative sample of 4065 individuals aged 15years or older. The participation rate was 87.5%. Interviews were conducted using the Sleep-EVAL system. The questions were related to sociodemographic characteristics, sleep-wake schedule, events occurring during sleep, insomnia symptoms, daytime consequences and DSM-IV diagnoses of sleep disorders.

RESULTS: Overall, 20.8% (95% C.I. 19.6-22.1%) of the sample reported at least one insomnia symptom occurring at least three nights/week. The prevalence was higher in women than in men (23.9% vs. 17.6%) and increased with age. Difficulty maintaining sleep at least three nights/week was the most prevalent symptom. DSM-IV insomnia disorder diagnoses were found in 6.4% (95% C.I. 5.6-7.1%) of the sample. Delayed bedtime and wake-up time, irregular bedtime hours and hypnagogic hallucinations were the most frequent in participants who had difficulty initiating sleep. Perception of light and "too short" sleep were the most frequent in participants who had early morning awakenings. Participants who had a non-restorative sleep were more likely to extend sleep on days off than other insomnia participants. Medical consultations in the previous year were more frequent in insomnia participants compared to participants without insomnia. One-fifth of insomnia participants were using sleep-promoting medication.

CONCLUSIONS: Insomnia is frequent in Spain, affecting up to one in five individuals. Results show that insomnia is multidimensional and needs to be assessed as such.




JOURNAL: Sleep Med. 2010 Dec;11(10):980-6.
TITLE: Prevalence and correlates of insomnia in the Swedish population aged 19-75 years.
AUTHOR(S): Ohayon MM, Bader G.


OBJECTIVE: To assess the prevalence of insomnia symptoms, their associated factors and daytime symptoms in the general population of Sweden.

METHODS: This is a cross-sectional postal survey performed in the general population of Sweden aged between 19 and 75years (6 million inhabitants). A total of 1209 out of 1705 randomly selected participants from the National Register of the Total Population completed the questionnaire. The participation rate was 71.3%. Participants filled out a paper-pencil questionnaire composed of 157 items covering sociodemographic characteristics, sleeping habits and environment, sleep quality and sleep symptoms, and health status.

RESULTS: We found 32.1% (95% confidence interval: 29.5-34.8%) of the sample reported having difficulty initiating (DIS) or maintaining sleep (DMS) or non-restorative sleep accompanied with sufficient sleep (NRS) at least 4 nights per week: 6.3% of the sample had DIS, 14.5% had DMS and 18.0% had NRS. Results from logistic regressions showed that restless legs symptoms, breathing pauses during sleep and depressive or anxious mood were associated with DIS and DMS but not NRS. Living in an urban area (OR:2.0) and drinking alcohol daily (OR:4.6) were associated only with NRS. Daytime symptoms were reported by over 75% of subjects with insomnia symptoms. DIS, DMS and NRS were associated with daytime fatigue but not excessive sleepiness as measured by the Epworth scale. DIS was associated with the use of sleeping pills or natural sleeping aid compounds in multivariate models.

CONCLUSIONS: Insomnia symptoms occurring at least 4 nights per week are frequent in Sweden, affecting about a third of the population. Subjects with NRS have a distinctly different profile than those with DIS or DMS, which suggests different etiological causes for this symptom.




JOURNAL: Sleep Med. 2010 Oct;11(9):941-6.
TITLE: Violent behavior during sleep: prevalence, comorbidity and consequences.
AUTHOR(S): Ohayon MM, Schenck CH.


BACKGROUND: Violent behaviors during sleep (VBS) are consequences of several sleep disorders but have received little attention in epidemiologic studies. This study aims to determine the prevalence of VBS in the general population and their comorbidity, familial links, course and treatment.

METHODS: Random stratified sample of 19,961 participants, 15 years and older, from the general population of Finland, Germany, Italy, Portugal, Spain and the United Kingdom were interviewed by telephone using the Sleep-EVAL Expert System. They answered a questionnaire on VBS, their consequences and treatment. Parasomnias and sleep and mental disorders were also evaluated.

RESULTS: VBS was reported by 1.6% (95% confidence interval: 1.4-1.7%) of the sample. VBS was higher in subjects younger than 35 years. During VBS episodes, 78.7% of VBS subjects reported vivid dreams and 31.4% hurt themselves or someone else. Only 12.3% of them consulted a physician for these behaviors. In 72.8% of cases, VBS were associated with other parasomnias (highest odds of VBS for sleepwalking and sleep terrors). Family history of VBS, sleepwalking and sleep terrors was reported more frequently in VBS than in non-VBS subjects with odds of 9.3, 2.0 and 4.2, respectively.

CONCLUSIONS: VBS are frequent in the general population and often associated with dream-enactment, sleepwalking and sleep terrors. High frequency of VBS, sleepwalking and sleep terrors in family of VBS subjects indicated that some families have a greater vulnerability to sleep disorders involving motor dyscontrol. Subjects who consulted a physician for these behaviors mostly received inappropriate or no support, indicating a lack of knowledge about VBS.




JOURNAL: Chronobiol Int. 2010 May;27(3):575-89.
TITLE: Consequences of shiftworking on sleep duration, sleepiness, and sleep attacks.
AUTHOR(S): Ohayon MM, Smolensky MH, Roth T.


Rotating shift and permanent night work arrangements are known to compromise sleep.

This study examined the effects of work schedule on sleep duration, excessive sleepiness, sleep attacks, driving, and domestic/professional accidents.
A representative sample of the general population of the state of New York--3,345 individuals > or = 18 yrs of age--was interviewed by telephone regarding their sleep and psychiatric and organic disorders. Multivariate models were applied to derive odds ratios (OR) after adjustment for age, sex, physical illness, mental disorders, obstructive sleep apnea, and sleep duration.

On average (+/-SE), workers slept 6.7 +/- 1.5 h, but 40% slept < 6.5 h/main sleep episode. Short-sleep duration (< 6 h) was strongly associated with fixed night (OR: 1.7) and day-evening-night shiftwork arrangement (OR: 1.9). Some 20% of the workers manifested excessive sleepiness in situations requiring high attention, and it was associated with the fixed night (OR: 3.3) and day-evening-night work arrangements (OR: 1.5). Overall, 5% of the workers reported sleep attacks; however, they occurred three-times more frequently in the fixed night (15.3%) than other work arrangements (OR: 3.2). Driving accidents during the previous 12 months were reported by 3.6% of the workers and were associated with fixed night (OR: 3.9) and day-evening-night (OR: 2.1) work schedules.

The findings of this study indicate that working outside the regular daytime hours was strongly associated with shorter sleep duration, sleepiness, and driving accident risk. Night work is the most disrupting, as it is associated with insufficient sleep during the designated rest span and excessive sleepiness and sleep attacks during the span of activity, with an associated consequence being increased driving accident risk.




JOURNAL: J Psychosom Res. 2010 Mar;68(3):235-43.
TITLE: Social phobia and depression: prevalence and comorbidity.
AUTHOR(S): Ohayon MM, Schatzberg AF.


BACKGROUND: Social phobia may seriously impair the functioning of affected individuals. It is frequently associated with other mental disorders.

AIMS: To estimate the co-occurrence of social phobia with major depressive disorder (MDD) and to analyze their interaction.

METHOD: Subjects were 18,980 individuals, aged 15 years or older, representative of the general population of the United Kingdom, Germany, Italy, Spain and Portugal, who were interviewed by telephone. DSM-IV diagnoses were made with the Sleep-EVAL system.

RESULTS: The point prevalence for social phobia was 4.4% (95% confidence interval: 4.1-4.7%) of the sample. It was higher in women (odds ratio: 1.6) and decreased with age. MDDs were found in 19.5% of participants with social phobia. Co-occurrence of another anxiety disorder was high and increased when a MDD was present (65.2%). The odds of developing a major depressive episode 2 years after the appearance of the social phobia was of 5.74.

CONCLUSIONS: Social phobia is highly prevalent in the general population. It increases the risk of developing a MDD and has a high comorbidity with other mental disorders. Social phobia is often present in the course of depression, more obviously during remission period of MDD. Physicians must explore and treat more systematically this frequent pathology.




JOURNAL: J Psychiatr Res. 2010 May;44(7):454-61.
TITLE: Chronic pain and major depressive disorder in the general population.
AUTHOR(S): Ohayon MM, Schatzberg AF.


This study aims:
(1) to assess the prevalence of Chronic Painful Physical Condition (CPPC) and major depressive disorder (MDD) in the general population;
(2) to evaluate their interaction and co-morbidity with sleep and organic disorders; and
(3) to investigate their daily functioning and socio-professional consequences.

A random sample of 3243 subjects (18years), representative of California inhabitants, was interviewed by telephone. CPPC duration was at least 6months. Frequency, severity, duration and consequences on daily functioning, consultations, sick leave and treatment were investigated. MDD were assessed using DSM-IV criteria. The point prevalence of CPPC was 49% (95% confidence interval: 47.0-51.0%). Back area pain was the most frequent; 1-month prevalence of MDD was at 6.3% (95% CI: 5.5-7.2%); 66.3% of MDD subjects reported at least one CPPC. In 57.1% of cases, pain appeared before MDD. Pain severity was increased by poor sleep, stress and tiredness in MDD subjects. Being confined to bed, taking sick leave and interference of pain with daily functioning were twice as frequent among MDD subjects with CPPC than in non-MDD subjects with CPPC; obese individuals with CP were 2.6 times as likely to have MDD.

Pain is highly linked with depressive disorder. It deteriorates physical, occupational and socio-professional activities. Pain and sleep disturbances are a prime motive of consultation rather than depressed mood, underlining the risk of missing a depression diagnosis.




JOURNAL: Sleep Med. 2010 Mar;11(3):236-41.
TITLE: Using difficulty resuming sleep to define nocturnal awakenings.
AUTHOR(S): Ohayon MM, Krystal A, Roehrs TA, Roth T, Vitiello MV.


Comment in: Sleep Med. 2010 Mar;11(3):229-30.

OBJECTIVE: Nocturnal awakenings are one of the most prevalent sleep disturbances in the general population. Little is known, however, about the frequency of these episodes and how difficulty resuming sleep once awakened affects subjective sleep quality and quantity.

METHOD: This is a cross-sectional telephone study with a representative sample consisting of 8937 non-institutionalized individuals aged 18 or over living in Texas, New York and California. The interviews included questions on sleeping habits, health, sleep and mental disorders. Nocturnal awakenings were evaluated according to their frequency per week and per night, as well as their duration.

RESULTS: A total of 35.5% of the sample reported awakening at least three nights per week. Of this 35.5%, 43% (15.2% of the total sample) reported difficulty resuming sleep once awakened. More than 80% of subjects with insomnia symptoms (difficulty initiating or maintaining sleep or non-restorative sleep) also had nocturnal awakenings. Difficulty resuming sleep was associated with subjective shorter sleep duration, poorer sleep quality, greater daytime impairment, greater consultations for sleep disturbances and greater likelihood of receiving a sleep medication.

CONCLUSIONS: Nocturnal awakenings disrupt the sleep of about one-third of the general population. Using difficulty resuming sleep identifies individuals with significant daytime impairment who are most likely to seek medical help for their sleep disturbances. In the absence of other insomnia symptoms, nocturnal awakenings alone are unlikely to be associated with daytime impairments.




JOURNAL: Sleep Med. 2009 Oct;10(9):952-60.
TITLE: Epidemiological and clinical relevance of insomnia diagnosis algorithms according to the DSM-IV and the International Classification of Sleep Disorders (ICSD).
AUTHOR(S): Ohayon MM, Reynolds CF 3rd.


Erratum in: Sleep Med. 2010 Feb;11(2):227.
Comment in: Sleep Med. 2009 Oct;10(9):941-2.

BACKGROUND: Although the epidemiology of insomnia in the general population has received considerable attention in the past 20 years, few studies have investigated the prevalence of insomnia using operational definitions such as those set forth in the ICSD and DSM-IV, specifying what proportion of respondents satisfied the criteria to reach a diagnosis of insomnia disorder.

METHODS: This is a cross-sectional study involving 25,579 individuals aged 15 years and over representative of the general population of France, the United Kingdom, Germany, Italy, Portugal, Spain and Finland. The participants were interviewed on sleep habits and disorders managed by the Sleep-EVAL expert system using DSM-IV and ICSD classifications.

RESULTS: At the complaint level, too short sleep (20.2%), light sleep (16.6%), and global sleep dissatisfaction (8.2%) were reported by 37% of the subjects. At the symptom level (difficulty initiating or maintaining sleep and non-restorative sleep at least 3 nights per week), 34.5% of the sample reported at least one of them. At the criterion level, (symptoms+daytime consequences), 9.8% of the total sample reported having them. At the diagnostic level, 6.6% satisfied the DSM-IV requirement for positive and differential diagnosis. However, many respondents failed to meet diagnostic criteria for duration, frequency and severity in the two classifications, suggesting that multidimensional measures are needed.

CONCLUSIONS: A significant proportion of the population with sleep complaints do not fit into DSM-IV and ICSD classifications. Further efforts are needed to identify diagnostic criteria and dimensional measures that will lead to insomnia diagnoses and thus provide a more reliable, valid and clinically relevant classification.




JOURNAL: J Psychiatr Res. 2009 Jul;43(10):934-40.
TITLE: Difficulty in resuming or inability to resume sleep and the links to daytime impairment: definition, prevalence and comorbidity.
AUTHOR(S): Ohayon MM.


OBJECTIVES: To assess the chronicity and severity of nocturnal awakenings with difficulty resuming sleep (DRS), its value as an indicator of an ongoing sleep and/or mental disorder and, finally, how it affects on daytime functioning.

METHODS: A cross-sectional telephone study was performed in the non-institutionalized general population of France, the United Kingdom, Germany, Italy and Spain. This representative sample of 22,740 non-institutionalized individuals aged 15 or over was interviewed on their sleeping habits, health, sleep and mental disorders. These five European countries totaled 245.1 million inhabitants. The evaluation of nocturnal awakenings with DRS included duration, frequency (per night, per week and in the previous months) and assessment scale of daytime functioning. DRS was defined as a complaint of difficulty in resuming or inability to resume sleep occurring at least three nights per week and lasting for at least one month.

RESULTS: A total of 16.1% [95% CI: 15.6-16.6] of the sample had DRS. Prevalence was higher in women and increased with age. The average duration of DRS was 40 months. DRS individuals slept on average 30 min less than other subjects with insomnia symptoms and 60 min less than the rest of the sample. Painful physical conditions, anxiety and mood disorders were the most discriminative factors for individuals with DRS distinguishing them from other insomnia subjects and the rest of the sample. Daytime impairment was observed in 52.2% of DRS individuals compared to 32.8% in individuals with classical insomnia symptoms (p < 0.0001).

CONCLUSIONS: (1) DRS affect a large segment of the population; (2) it is a good indicator of an ongoing sleep or mental disorder; (3) it has a stronger impact on daytime functioning than classical insomnia symptoms (OR: 4.7).




JOURNAL: J Psychiatr Res. 2008 Nov;43(1):48-54.
TITLE: Nocturnal awakenings and comorbid disorders in the American general population.
AUTHOR(S): Ohayon MM


OBJECTIVE: Nocturnal awakenings are one of the most prevalent sleep disturbances in the general population. However, little is know about how its severity affects co-morbidity with mental disorders and organic diseases.

METHODS: A representative sample consisting of 8937 non-institutionalized individuals aged 18 or over living in Texas, New York and California states were interviewed by telephone. The interviews included sleeping habits, health, sleep and mental disorders. Nocturnal awakenings were evaluated according to their frequency per week and per night, their duration and the motive(s) for the awakenings.

RESULTS: A total of 35.5% of the sample reported awakening at least 3 nights per week: 23% of reported awakening at least one time every night; 4.5% 5 or 6 nights per week and 7.9% 3 or 4 nights per week. Nocturnal awakenings increased with age only among people with nightly awakenings and were more frequent among women than men only among those awakening every night. More than 90% of subjects reported this problem lasted for more than 6 months. About 40% of subjects with nocturnal awakenings also reported other insomnia symptoms. Generally speaking, organic diseases and psychiatric disorders were more frequent among subjects waking up at least 3 nights per week regardless the frequency of nocturnal awakenings. However, nightly nocturnal awakenings were associated with more frequent organic diseases, obesity and psychiatric disorders.

CONCLUSIONS: Nocturnal awakenings disrupt the sleep of about one third of the general population. Nocturnal awakenings are associated with a wide variety of organic diseases and psychiatric disorders that warrant appropriate treatment.




JOURNAL: Sleep Med Rev. 2008 Apr;12(2):129-41.
TITLE: From wakefulness to excessive sleepiness: what we know and still need to know.
AUTHOR(S): Ohayon MM


The epidemiological study of hypersomnia symptoms is still in its infancy; most epidemiological surveys on this topic were published in the last decade. More than two dozen representative community studies can be found. These studies assessed two aspects of hypersomnia: excessive quantity of sleep and sleep propensity during wakefulness excessive daytime sleepiness.

The prevalence of excessive quantity of sleep when referring to the subjective evaluation of sleep duration is around 4% of the population. Excessive daytime sleepiness has been mostly investigated in terms of frequency or severity; duration of the symptom has rarely been investigated. Excessive daytime sleepiness occurring at least 3 days per week has been reported in between 4% and 20.6% of the population, while severe excessive daytime sleepiness was reported at 5%. In most studies, men and women are equally affected. In the International Classification of Sleep Disorders, hypersomnia symptoms are the essential feature of three disorders: insufficient sleep syndrome, hypersomnia (idiopathic, recurrent or posttraumatic) and narcolepsy. Insufficient sleep syndrome and hypersomnia diagnoses are poorly documented. The co-occurrence of insufficient sleep and excessive daytime sleepiness has been explored in some studies and prevalence has been found in around 8% of the general population. However, these subjects often have other conditions such as insomnia, depression or sleep apnea. Therefore, the prevalence of insufficient sleep syndrome is more likely to be between 1% and 4% of the population. Idiopathic hypersomnia would be rare in the general population with prevalence, around 0.3%. Narcolepsy has been more extensively studied, with a prevalence around 0.045% in the general population. Genetic epidemiological studies of narcolepsy have shown that between 1.5% and 20.8% of narcoleptic individuals have at least one family member with the disease. The large variation is mostly due to the method used to collect the information on the family members; systematic investigation of all family members provided higher results.

There is still a lot to be done in the epidemiological field of hypersomnia. Inconsistencies in its definition and measurement limit the generalization of the results. The use of a single question fails to capture the complexity of the symptom. The natural evolution of hypersomnia remains to be documented.




JOURNAL: NeuroPsy News 2008; 7: 63-70.
TITLE: Comportements violents ou dangeureux durant le sommeil [Violent or dangerous behaviors during sleep].
AUTHOR(S): Ohayon MM


Violent or harmful behaviors during sleep remain scantly studied. However, nearly 2% of the general population reports experiencing such behaviors. Violent behaviors cover a broad range of phenomena, including relatively benign dream enactment, self-mutilation, murder and suicide. Such behaviors can occur in several types of sleep disorders such as sleepwalking, night terrors, confusional arousals, sleep-related epilepsy and REM sleep behavior disorder. This article reviews these disorders and summarizes the conclusions of epidemiological and clinical studies conducted with patients having violent or harmful behaviors during their sleep.




JOURNAL: Int J Sleep Wakefulness - Prim Care 2008; 1:141-145.
TITLE: Sleep disturbances and their impact on medical disease and morbidity.
AUTHOR(S): Ohayon MM


In general population, insomnia complaints are reported by near the third of the population, it translated into a diagnosis of insomnia for only 6% to 15% of the population. Similarly, excessive daytime sleepiness is reported by about 20% of the population but only 2% have a diagnosis of hypersomnia, narcolepsy or insufficient sleep syndrome. In the overwhelming majority of these individuals, sleep disturbances rarely occur alone and are frequently caused or associated with various medical or neurological diseases, psychiatric disorders and environmental factors. It is therefore imperative to diagnose these co-morbid conditions as part of an appropriate planning of the treatment.




JOURNAL: Rev Prat. 2007 Sep 30;57(14):1521-8.
TITLE: [Prevalence and comorbidity of sleep disorders in general population]
AUTHOR(S): Ohayon MM


Sleep disorders can be expressed in different ways. The International Classification of Sleep Disorders lists more than 80 different sleep disorder diagnoses.

In general population, although the insomnia complaint is reported by nearly the third of the population, it is translated into a diagnosis of insomnia for only 6% to 15% of the population. Sleep apnea syndrome, often associated with insomnia or daytime sleepiness, is found in approximately 2% to 4% of the general population. Restless legs syndrome is present for approximately 6% of the general population with a higher prevalence in the elderly subject. Narcolepsy is rare with a prevalence of 0.04%. Parasomnias are less studied in the general population; prevalences of several of parasomnias remain unknown. Among those more extensively studied, sleep paralysis is found for approximately 6% of the general population. Nocturnal terrors, the confusional arousals and nightmares have been observed with prevalences ranging from 2.2% to 5%.

Despite their high frequency, sleep disorders remain poorly identified; less than 20% of individuals with sleep disorders are correctly diagnosed and treated.




JOURNAL: Medicographia 2007; 29:10-16.
TITLE: Epidemiology of circadian rhythm disorders in depression.
AUTHOR(S): Ohayon MM


Depression is a serious disabling disease that will affect nearly one on seven individuals during lifetime and that is currently affecting about one on 20 adults in North America and Western Europe. It is one of the top three leading causes of disability in industrialized countries. The prevalence is higher in women and is lower in elderly people.

Insomnia symptoms are common in the general population. About one third of the adult population reports having mild to important difficulty falling asleep or maintaining sleep.

Between 9% and 15% of the population have daytime consequences associated with insomnia and between 8% and 18% of the general population is dissatisfied with its sleep. The prevalence of insomnia generally increases with age and is higher in women than in men. The association between insomnia and depression has been constantly reported: individuals with insomnia are more likely to have a major depressive illness and depressed individuals report insomnia symptoms in up to 80% of the cases.

Longitudinal studies have shown that the persistence of insomnia is associated with the appearance of a new depressive episode in the next year. Very few epidemiological studies have attempted to describe which type of insomnia characterized depressed individuals. None of them have investigated abnormalities in the sleep/wake schedule to determine if circadian rhythm disturbances could be present.




JOURNAL: J Psychiatr Res. 2007 Apr-Jun;41(3-4):207-13.
TITLE: Epidemiology of depression and its treatment in the general population.
AUTHOR(S): Ohayon MM


This study examines the correlates of a major depressive disorder and its treatment in the general population. The sample was composed of 6694 individuals aged between 18 and 96 years, representative of the general population of the states of California and New York (48 million inhabitants aged 18 years or older). They were interviewed by telephone using the Sleep-EVAL system. The interviews included various sleep and health topics and the assessment of DSM-IV sleep and psychiatric disorders.
The 1-month prevalence of a major depressive disorder was 5.2% in the sample, and was higher in women, middle-aged and non-Hispanic white individuals. Obesity (BMI > or =30kg/m(2)), poor health status and smoking were also strongly correlated with a major depressive disorder. A total of 57.7% of depressed subjects were receiving some forms of treatment for depression: 28.3% were taking antidepressants (alone or in combination with psychiatric health care) and 29.4% received psychiatric health care (without antidepressant medication). Severity of depression, ethnicity and weight (overweight or obese) were strongly associated with the presence of treatment.

A major depressive disorder is frequent in the general population. Although its identification and treatment have improved over the years, some segments of the population, namely elderly and non-white individuals are less likely to receive appropriate care.




JOURNAL: Int J Sleep Disorders 2006; 1:16-21.
TITLE: Chronic pain and sleep.
AUTHOR(S): Ohayon MM


Sleep disturbances are common in individuals experiencing chronic pain.

Subjective measures of sleep in various chronic pain conditions mostly demonstrate a high number of complaints of disrupted and unrefreshing sleep. Polysomnographic studies of patients with chronic pain have been less conclusive; many studies have shown that patients with chronic pain have a fragmented slow wave sleep with intrusion of alpha waves, while others report few perceptible changes in the sleep of patients with chronic pain. Experimental studies in healthy humans have shown that the pain-sleep relationship is bidirectional: pain stimuli provoke changes in sleep architecture and partial or complete sleep deprivation lowers pain thresholds in healthy individuals.




JOURNAL: Neurology. 2006 Aug 22;67(4):703-5.
TITLE: Occurrence of sleep disorders in the families of narcoleptic patients.
AUTHOR(S): Ohayon MM, Okun ML.


First-degree relatives of narcoleptic subjects (probands) may have sleep pathology related to the transmission of the disorder through their family members.

The authors examined four groups: probands (n = 96), first-degree relative (n = 337), environmental reference (n = 85), and general population (n = 6,694) groups. Compared with the general population, family members have a 75-fold increased risk for narcolepsy. They are also at greater risk for insufficient sleep syndrome (odds ratio [OR] 6.1), nocturnal eating (OR 5.7), and adjustment sleep disorder (OR 3.1).




JOURNAL: Arch Intern Med. 2006 Jun 26;166(12):1262-8.
TITLE: Severe hot flashes are associated with chronic insomnia.
AUTHOR(S): Guilleminault C, Kirisoglu C, Poyares D, Palombini L, Leger D, Farid-Moayer M, Ohayon MM


BACKGROUND: Because hot flashes can occur during the night, their presence has been frequently associated with insomnia in women with symptoms of menopause. However, many factors other than hot flashes or menopause can be responsible for insomnia, and several factors associated with insomnia in the general population are also commonly observed in perimenopausal and postmenopausal women who have hot flashes.
METHODS: A random sample of 3243 subjects (aged > or =18 years) representative of the California population was interviewed by telephone. Included were 982 women aged 35 to 65 years. Women were divided into 3 groups according to menopausal status: premenopause (57.2%), perimenopause (22.3%), and postmenopause (20.5%). Hot flashes were counted if they were present for at least 3 days per week during the last month and were classified as mild, moderate, or severe according to their effect on daily functioning. Chronic insomnia was defined as global sleep dissatisfaction, difficulty initiating sleep, difficulty maintaining sleep, or nonrestorative sleep, for at least 6 months. Diagnoses of insomnia were assessed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, classification.

RESULTS: Prevalence of hot flashes was 12.5% in premenopause, 79.0% in perimenopause, and 39.3% in postmenopause. Prevalence of chronic insomnia was reported as 36.5% in premenopause, 56.6% in perimenopause, and 50.7% in postmenopause (P<.001). Prevalence of symptoms of chronic insomnia increased with the severity of hot flashes, reaching more than 80% in perimenopausal women and postmenopausal women who had severe hot flashes. In multivariate analyses, severe hot flashes were significantly associated with symptoms and a diagnosis of chronic insomnia. Poor health, chronic pain, and sleep apnea were other significant factors associated with chronic insomnia.

CONCLUSIONS: Severe hot flashes are strongly associated with chronic insomnia in midlife women. The presence of hot flashes should be systematically investigated in women with insomnia. Treating hot flashes could improve sleep quality and minimize the deleterious consequences of chronic insomnia.




JOURNAL: J Psychiatr Res. 2006 Apr;40(3):273-9.
TITLE: Upper airway resistance syndrome: a long-term outcome study.
AUTHOR(S): Guilleminault C, Kirisoglu C, Poyares D, Palombini L, Leger D, Farid-Moayer M, Ohayon MM


This prospective study aimed to assess symptomatic evolution of patients diagnosed with Upper Airway Resistance Syndrome (UARS) four and half years after the initial UARS diagnosis. For this purpose, 138 UARS patients were contacted by mail between 43 and 69 months after the initial evaluation; 105 responded to the letter and 94 patients accepted to undergo new clinical and polysomnographic evaluations. Initial and follow-up polysomnographic recordings were scored using the same criteria.

RESULTS: Of the 94 patients who completed the follow-up examination, none of them were using nasal CPAP. It was related to refusal by insurance providers to provide equipment based on initial apnea-hypopnea index (AHI) in 90/94 subjects. Percentage of patients with sleep related-complaints significantly increased over the four and half year period: daytime fatigue, insomnia and depressive mood increased by 12 to 20 times. Reports of sleep maintenance sleep onset insomnia and depressive mood was significantly increased. Hypnotic, antidepressant and stimulant prescription increased from initial to follow-up visit (from 11.7% to 61.7%; from 3.2% to 25.5% and from 0% to 9.6%, respectively) with antidepressant given as much for sleep disturbance as mood disorder. The polysomnography results at follow-up showed that 5 subjects had AHI compatible with Obstructive Sleep Apnea Syndrome (OSAS) but overall, respiratory disturbance index had no significant change. Total sleep time was significantly reduced compared to initial visit.

CONCLUSIONS: Many UARS patients remained untreated following initial evaluation. Worsening of symptoms of insomnia, fatigue and depressive mood were seen with absence of treatment of UARS.




JOURNAL: J Sleep Res. 2005 Dec;14(4):437-45.
TITLE: Frequency of narcolepsy symptoms and other sleep disorders in narcoleptic patients and their first-degree relatives.
AUTHOR(S): Ohayon MM, Ferini-Strambi L, Plazzi G, Smirne S, Castronovo V.


Narcolepsy is a rare neurological sleep disorder affecting around 0.05% of the general population. Genetic factors are known to have an important role in narcolepsy. However, because of its very low prevalence, it is difficult to have groups of comparison between first-degree relatives and general population subjects in order to identify a specific spectrum of disorders in these families.

Consequently, from 157 Italian patients with narcolepsy, 263 first-degree relatives were recruited, two refused to participate. These family members were compared with a matched group of 1071 subjects selected from a sample of 3970 subjects representative of the general population of Italy (46 million inhabitants). Finally, 68 spouses of narcoleptic patients were used to assess for possible role of environmental factors. All subjects were interviewed by telephone using the Sleep-EVAL system.

Nineteen cases of narcolepsy were discovered among the first-degree relatives of 17 probands (10.8%). Compared with the general population subjects, the relative risk of narcolepsy among female first-degree relatives was of 54.4 and of 105.1 among male first-degree relatives. First-degree relatives were also at higher risk for idiopatic hypersomnia (OR: 23.0), obstructive sleep apnea syndrome (OR: 6.8), adjustment sleep disorder (OR: 4.0), insufficient sleep syndrome (OR: 7.0), circadian rhythm disorders (OR: 2.5), REM behavior disorder (OR: 4.4), and sleep talking (OR: 2.0).

The vulnerability to sleep disorders is very high in first-degree relatives and the link with different expressivity and severity of hypersomnia can be confirmed.




JOURNAL: J Psychosom Res. 2005 Dec;59(6):399-405.
TITLE: How age influences the expression of narcolepsy.
AUTHOR(S): Ohayon MM, Ferini-Strambi L, Plazzi G, Smirne S, Castronovo V..


OBJECTIVES: The aim of this study was to investigate the influence of age on the manifestation of narcolepsy symptoms and cognitive difficulties in patients with narcolepsy.

METHODS: A total of 321 participants were included in the study: 157 were patients with narcolepsy from two Sleep Disorders Clinics and 164 were control participants. Narcoleptic patients were evaluated and diagnosed at the Sleep Disorders Clinic. All participants were interviewed by telephone using the Sleep-EVAL System. The interview comprised, among else, a detailed evaluation of narcolepsy symptoms and of cognitive difficulties.

RESULTS: The first manifestation of the disease appeared early in life for most narcoleptic patients: 54.1% had their first symptom before the age of 20 years. Daytime sleepiness was the first symptom to appear in 65.5% of cases. In narcoleptics 60 years or older, cataplexy was more likely to be the first symptom to appear (47.4%) compared with other narcoleptic patients (21.4%; P<.05). Reported cognitive difficulties (attention-concentration, praxis, delay recall, orientation for persons, temporal orientation, and prospective memory) were higher in narcoleptic patients compared with the controls. The severity of daytime sleepiness and the presence of a major depressive disorder partly explained the cognitive difficulties. However, attention-concentration deficits and difficulties in prospective memory remained significant. Age was unrelated to cognitive difficulties in narcoleptics patients.

CONCLUSIONS: The first manifestation of narcolepsy appears early in life. Reported cognitive difficulties are important in narcoleptic patients and are only partly explained by age, severity of daytime sleepiness, and major depressive disorder.




JOURNAL: Arch Intern Med. 2005 Jan 10;165(1):35-41.
TITLE: Prevalence and correlates of nonrestorative sleep complaints.
AUTHOR(S): Ohayon MM


BACKGROUND: Nonrestorative sleep (NRS) has been little studied in the general population, even though this symptom has an important role in several medical conditions such as heart disease, fibromyalgia, and chronic fatigue syndrome, as well as various sleep disorders.

METHODS: A total of 25,580 individuals (age range, 15-100 years) from the noninstitutionalized general population representative of 7 European countries (France, the United Kingdom, Germany, Italy, Portugal, Spain, and Finland) were interviewed by telephone using the Sleep-EVAL system. Nonrestorative sleep was analyzed in relationship to sociodemographic determinants, environmental factors, life habits, health, sleep-wake schedule, and psychological factors.

RESULTS: The prevalence of NRS was 10.8% (95% confidence interval, 10.4%-11.2%) in the sample, was higher in women than in men (12.5% vs 9.0%; P<.001), and decreased with age. The United Kingdom (16.1%) and Germany (15.5%) had the highest prevalence of NRS and Spain (2.4%), the lowest. In multivariate analyses, several factors were positively associated with NRS. The most important were younger age, dissatisfaction with sleep, difficulty getting started in the morning, stressful life, presence of anxiety, bipolar or a depressive disorder, and having a physical disease. When compared with subjects who have difficulty initiating or maintaining sleep (without NRS), subjects with NRS reported more frequently a variety of daytime impairment (irritability, physical, and mental fatigue) and consulted a physician twice as frequently for their sleeping difficulties than did other subjects with insomnia.

CONCLUSIONS: Nonrestorative sleep is a frequent symptom in the general population, but its prevalence largely varies between countries. It is often associated with mental disorders and characteristics of sleep deprivation (such as extra sleep time on weekends). Nonrestorative sleep affected more frequently the active classes of the population and caused greater daytime impairment than difficulty initiating or maintaining sleep.




JOURNAL: Sleep. 2004 Dec 15;27(8):1507-11.
TITLE: C-reactive protein and sleep-disordered breathing.
AUTHOR(S): Guilleminault C, Kirisoglu C, Ohayon MM.


STUDY OBJECTIVES: Over a 2-month period, to evaluate serum levels of C-reactive protein (CRP) in new patients with obstructive sleep apnea syndrome (OSAS), upper airway resistance syndrome (UARS), and absence of important comorbidity, as well as in normal controls. DESIGN: Cross-sectional analysis.

SETTING: Sleep disorders clinic. PATIENTS: 239 successively monitored subjects: 156 subjects were diagnosed with OSAS, 39 with UARS, and 54 controls. INTERVENTIONS: none. MEASUREMENTS AND

RESULTS: Clinical information (neurologic, general medical, and otolaryngology examination), body mass index, neck circumference, hip-waist ratio, Epworth Sleepiness Scale, 3 fatigue scales, Sleep Disorders Questionnaire, serum CRP, and polysomnography were collected. Analysis of variance indicated a significant difference between the groups for diastolic blood pressure, respiratory disturbance index, lowest SaO2, and body mass index. The mean serum CRP level was normal in all 3 groups. Only 15 (14 OSAS and 1 UARS) out of 239 subjects had high serum CRP values. CRP levels were significantly correlated with body mass index, esophageal pressures, hip-waist ratio, neck circumference, and blood pressure. Only body mass index was significantly associated with high CRP values; multiple regression showed: adjusted R2 = 0.115, beta = 0.345, P <.001. When men and women were considered separately, body mass index was again significantly associated with high CRP levels.

CONCLUSION: Obesity is a risk factor for high serum CRP levels in patients with sleep-disordered breathing, as in the general population.




JOURNAL: J Psychiatr Res. 2006 Feb;40(1):30-6.
TITLE: Prevalence of major depressive disorder in the general population of South Korea.
AUTHOR(S): Ohayon MM, Hong SC.


INTRODUCTION: Previous epidemiological studies have reported a high prevalence of major depressive disorder (MDD) in North America and Western Europe. However, little information exists on MDD in Asian countries. This study investigates the prevalence of MDD and its characteristics in the general population of South Korea.

METHODS: A representative sample of the South Korean general population composed of 3719 non-institutionalized individuals aged 15 years or older was interviewed by telephone using the Sleep-EVAL system. The participation rate was 91.4%. The interviews covered sociodemographic characteristics, health care utilization, physical illnesses and Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) psychiatric disorders.

RESULTS: A depressive mood, i.e., feeling sad, downcast, having the blues or having lost interest in things formerly pleasant was reported by 20.9% of the sample without significant difference between men and women and among age groups. DSM-IV MDD was found in 3.6% (95% CI: 3.0-4.2%) of the sample. The prevalence of MDD was comparable among age groups. Shift workers were more likely to have MDD than daytime workers. Factor significantly associated with MDD were: being a woman, being a light or heavy smoker, perceiving one's health as being average or poor, doing physical activities at least three times per week in the evening, having a BMI below 18.5 kg/m2 and perceiving one's life as being moderately or highly stressful.

CONCLUSIONS: Prevalence of MDD in Korea is higher than what it was previously estimated to be two decades ago. The number of individuals seeking help for depression was very low, and only a small number of MDD subjects received appropriate treatment for their condition.




JOURNAL: Sleep Med. 2005 Sep;6(5):435-41.
TITLE: Global sleep dissatisfaction for the assessment of insomnia severity in the general population of Portugal.
AUTHOR(S): Ohayon MM, Paiva T.


BACKGROUND AND PURPOSE: This study examines the prevalence and associated factors of insomnia symptoms and sleep dissatisfaction in the general population of Portugal.

PATIENTS AND METHODS: We interviewed by telephone 1858 participants aged 18 years or older and representative of the general population of Portugal using the Sleep-EVAL system. Participation rate was 83%. The questionnaire included the assessment of sleep habits, insomnia symptomatology according to DSM-IV and ICSD classifications, associated and sleep/mental disorders and daytime consequences.

RESULTS: Insomnia symptoms occurring at least 3 nights per week were reported by 28.1% of the sample and global sleep dissatisfaction (GSD) by 10.1%. Difficulty maintaining sleep was the most frequent symptom (21.0%); 29.4% of subjects with insomnia symptoms reported GSD. Daytime consequences, medical consultations for sleep and use of sleep medication were at least 2 times more frequent among subjects with insomnia symptoms and GSD compared to subjects with insomnia symptoms without GSD; insomnia diagnoses were also more frequent in the GSD group.

CONCLUSIONS: The results show a severity gradation among subjects with only 1 insomnia symptom, those with 2 or 3 insomnia symptoms but without GSD and those with at least 1 insomnia symptom and GSD. Specific sleep or psychiatric disorders were identified for the majority of GSD subjects (86%); this rate dropped to 50.6% when only 1 insomnia symptom without GSD was reported. GSD appeared to be a good indicator of the presence of a sleep or psychiatric disorder and a good discriminator of the severity of sleep disturbances among subjects with insomnia symptoms.




JOURNAL: Sleep. 2005 Aug;28(8):981-9.
TITLE: Normative sleep data, cognitive function and daily living activities in older adults in the community.
AUTHOR(S): Ohayon MM, Vecchierini MF.


STUDY OBJECTIVES: To present normative data of sleep-wake characteristics and to examine risk factors associated with extreme values (i.e., in the 5 lower and upper percentiles of the distribution) in older adults.

DESIGN: Cross-sectional telephone survey.

SETTING: The metropolitan area of Paris, France.

PARTICIPANTS: A total of 7010 randomly selected households were contacted. Among them, 1264 households included at least 1 resident 60 years of age or older; 1026 subjects agreed to participate (participation rate: 80.9%).

INTERVENTIONS: None.

MEASUREMENTS AND RESULTS: Subjects were interviewed with the Sleep-EVAL System about their sleeping habits and sleep and psychiatric disorders. In addition, the system administered to all the participants the Psychological General Well-Being Schedule, the Cognitive Difficulties Scale (Mac Nair-R), and an independent living scale. The median nighttime sleep duration was 7 hours without significant difference between the age groups. Factors positively associated with the 5 percentile (4 hours 30 minutes or less) of nighttime sleep duration were obesity, poor health, insomnia, and insomnia accompanied by daytime sleepiness and cognitive impairment. At the other extremity (95th percentile), long sleep (9 hours 30 minutes or more) was associated with organic disease, lack of physical exercise, and lower education. A daytime sleep duration of 1 hour or more (95th percentile) was associated with being a man, cognitive impairment, high blood pressure, obesity, and insomnia. Long sleep latency (95th percentile at 80 minutes) was associated with anxiety, lower education, poor health, insomnia without excessive daytime sleepiness, and obstructive sleep apnea syndrome. Obesity and loss of autonomy in activities of daily living was associated with both early (9 PM or earlier) and late bedtime (1 AM or later) and early (< or = 5 AM) and late (> or = 9 AM) wake-up time.

CONCLUSIONS: This study illustrates the usefulness of normal distributions of sleep parameters in the general population to calculate different risk factors associated with extreme values of the normal distribution.




JOURNAL: J Psychiatr Res. 2005;39(2):151-9.
TITLE: Relationship between chronic painful physical condition and insomnia
AUTHOR(S): Ohayon MM


Background: A chronic painful physical condition (CPPC) can be a major cause of sleep disturbances. Few community-based surveys examined the specific relationship between these two conditions.

Methods: 18,980 participants aged 15 years or older from five European countries (the United Kingdom, Germany, Italy, Portugal and Spain) and representative of approximately 206 millions Europeans were interviewed by telephone. The interview included questions about sleeping habits, health, sleep and mental disorders. Painful physical conditions were ascertained through questions about medical treatment, consultations and/or hospitalizations for medical reasons and a list of 42 diseases. A painful physical condition was considered chronic when it lasted at least six months. Insomnia symptoms were defined as difficulty initiating or maintaining sleep or non-restorative sleep, present at least 3 nights per week, lasting at least one month ,and accompanied by daytime consequences.

Results: 1) The point prevalence of at least one CPPC was set at 17.1% (95% CI: 16.5% to 17.6%) in the sample. 2) Difficulty initiating sleep was found in 5.1% (95% Confidence Intervals: 4.8% to 5.4%) of the sample, disrupted sleep in 7.5% (95% CI: 7.2% to 7.9%); early morning awakenings in 4.8% (95% CI: 7.2% to 7.9%) and non-restorative sleep in 4.5% (95% CI: 4.2% to 4.8%). 3) More than 40% of individuals with insomnia symptoms reported at least one CPPC. 4) CPPC was associated with more frequent difficulty or inability to resume sleep once awake and a shorter sleep duration. 5) In middle-aged subjects (45 to 64 years of age), CPPC was associated with longer insomnia duration. At any age, insomnia with CPPC was associated with a greater number of daytime consequences (average of four consequences) than in insomnia without CPPC (average of 2.3 consequences). 6) In multivariate models, CPPC, especially backaches and joint/articular diseases, were at least as importantly associated with insomnia than were mood disorders with odds ratios ranging from 4.1 to 5.0 for backaches and from 3.0 to 4.8 for joint/articular diseases.

Conclusions: CPPC is associated with a worsening of insomnia on several aspects: a greater number of insomnia symptoms, more severe daytime consequences and more chronic insomnia situation. CPPC plays a major role on insomnia. Its place as major contributive factor for insomnia is as much important as mood disorders.




JOURNAL: Sleep. 2004 Nov;
TITLE: Meta-Analysis Of Quantitative Sleep Parameters From Childhood To Old Age In Healthy Individuals: Developing Normative Sleep Values Across The Human Lifespan
AUTHOR(S): Ohayon MM, Carskadon MA, Guilleminault C, Vitiello MV


Objectives: The purposes of this study were to identify age-related changes in objectively recorded sleep patterns across the human life span in healthy individuals and to clarify whether sleep latency, percentages of stage 1, stage 2 and REM sleep significantly change with age.

Design: Review of literature of articles published between 1960 and 2003 in peer-reviewed journals and meta-analysis. Participants: 65 studies representing 3,577 subjects aged 5 years to 102 years.

Measurement: The research reports included in this meta-analysis met the following criteria: a) included non-clinical participants aged five years or older; b) included measures of sleep characteristics by "all night" polysomography (PSG) or actigraphy on sleep latency (SL), sleep efficiency (SE), total sleep time (TST), stage 1, stage 2, slow wave sleep (SWS), REM, REM latency, or minutes awake after sleep onset (WASO); c) included numeric presentation of the data; d) were published between 1960 and 2003 in peer-reviewed journals. Results: In children and adolescents, total sleep time decreased with age only in studies performed on school days. Percentage of SWS was significantly negatively correlated with age. Percentages of stage 2 and REM sleep significantly changed with age. In adults, total sleep time, sleep efficiency, %SWS, %REM sleep and REM latency all significantly decreased with age; while sleep latency, % stage 1, % stage 2 and WASO significantly increased with age. However, only sleep efficiency continued to significantly decrease after 60 years of age. The magnitudes of the effect sizes noted changed depending on whether or not studied participants were screened for mental disorders, organic diseases, use of drug or alcohol, OSAS, or other sleep disorders.

Conclusions: It appeared that sleep latency, percentages of stage 1, stage 2 and REM sleep significantly increased with age. However, effect sizes for the different sleep parameters were greatly modified by the quality of subject screening, diminishing or even masking age associations with different sleep parameters. The number of studies that examine the evolution of sleep parameters with age are scant among school-aged children, adolescents and middle-aged adults. There are also very few studies that examined the effect of race on PSG sleep parameters.




JOURNAL: Encephale. 2004 Mar-Apr;30(2):135-40
TITLE: [Sleep and insomnia markers in the general population]
AUTHOR(S): Ohayon MM, Lemoine P.


Several epidemiological surveys performed in Western Europe reported a prevalence of insomnia symptoms between 20% and 40% of the general population. Women and elderly individuals were the most affected. Many events can occur during sleep and affect its quality. Daytime sleepiness, a consequence of lack of sleep and/or insomnia, is responsible for many road, work and domestic accidents. Therefore, insomnia may have important consequences both for individuals and society.

This study performed in the non institutionalized French population reports the sleep habits of that population and the factors associated with insomnia. This epidemiological study was conducted with 5622subjects representative of the French general population. They were aged between 15 and 96 Years. The participation rate was 80.8%.

The results showed that men and women have different sleep habits. Generally speaking, women went to bed about 12 minutes earlier than men and woke up later than men (p<0.001). Women also took more time to fall asleep than men but only when they were aged between 35 and 65 Years. Furthermore, women had a longer sleep than men except between the ages of 55 and 74, where men slept significantly more than women. However, sleep efficiency was lower in women than in men who were over age 35. This was due to a greater frequency of nocturnal awakenings in women than in men. Sleep habits also changed with age: Bedtime became progressively earlier with advancing age and wake-up time was later when the subjects reached retirement age. Sleep latency progressively increased with age after 35. Similarly, disrupted sleep increased with age and was reported by more than half of subjects 75 Years or older. We found also that evening or night workers showed irregularities in their sleep patterns: sleep latency was significantly longer - at least 12 minutes - compared to daytime and shift workers (p<0.001). They also had a shorter sleep duration of about 30 minutes compared to shift workers, and 40 minutes compared to daytime workers (p<0.001). Shift workers and evening or night workers had a lower sleep efficiency compared to daytime workers. Finally, in regions with greater density population (>100000inhabi-tants) sleep duration was shorter by approximately 10 minutes compared to localities with fewer than 5 000 residents (p<0.01). Similarly, bedtime and wake up hours were more related in regions with more than 100 000 inhabitants compared to small localities (fewer than 5 000 residents). Insomnia complaints, defined as the presence of at least one insomnia symptom accompanied by sleep dissatisfaction or use of a sleep medication, were reported by 18.6% of the sample. The prevalence was higher in women (22.4%) than in men (14.5%) and increased with age. However, the proportion of subjects dissatisfied with their sleep remained comparable for all age groups; it was the number of subjects using a sleep medication that increased with age. This was 3.2% in subjects 44 Years or younger, 13.3% in subjects between 45 and 64 Years, 22% of those between 65 and 74 Years and almost a third of individuals 75 Years or older (32%; p<0.001). However, insomnia symptoms remained present for most of these consumers: 80.4% of those between 15 and 44 Years, 87.9% of those between 45 and 64 Years, 81.4% of those between 65 and 74 Years and 78.8% of subjects of 75 Years or older.

Compared to subjects in other epidemiological studies undertaken in England, Germany and Italy and using the same methodology, subjects in this study complained with their sleep more often. Insufficient sleep was found more often in the active population, which is subject to schedule constraints. Shift workers as well as evening or night workers were the most likely to have a sleep debt.




JOURNAL: J Psychiatr Res. 2004 May-Jun;38(3):327-34.
TITLE: Chronic benzodiazepine usage and withdrawal in insomnia patients.
AUTHOR(S): Poyares D, Guilleminault C, Ohayon MM, Tufik S.


We studied the sleep of patients with insomnia during continuous and very long-term use of benzodiazepines (BZDs), and after withdrawal.

A group of 25 patients (mean age 44.3+/-11.8 years) with persistent insomnia, who had been taking BZDs nightly for 6.8+/-5.4 years was selected. The control group was comprised of 18 age-matched healthy individuals. Sleep stage parameters were analyzed during Night 1 (while taking BZDs), Night 2 (first night after completing BZD withdrawal), and Night 3 (15 days after gradual BZD withdrawal). Sleep data for control subjects was monitored in parallel. Sleep EEGs of the patients were analyzed using Period Amplitude Analysis (PAA), during Nights 1 and 3 only.

During BZD use, a significant reduction of Total Sleep Time (TST) and increased sleep latency were found in the insomniac group when compared to controls. We found an increase in stage 2 non-REM (NREM) sleep, and a reduction in Slow Wave Sleep (SWS) when comparing to night 3 (after withdrawal). Sleep EEGs analysis showed an increase in sigma band and decrease in delta count in stages 2, 3, 4 NREM and REM sleep in the BZD group when comparing to night 3 (after withdrawal). During the BZD withdrawal period, six out of nine subjects taking lorazepam failed withdrawal. In the remaining 19 subjects, gradual withdrawal of BZDs was associated with immediate worsening of nocturnal sleep, as indicated by sleep parameters. However, 15 days after withdrawal (Night 3), some of the sleep structure parameters of patients were not significantly different from baseline (while taking BZDs), except for a significant increase in SWS and in delta count throughout most sleep stages, and a decrease in stage 2 NREM sleep. These values were not different from those shown by control subjects. REM sleep parameters showed no significant variation across the experimental conditions. Subjective sleep quality was significantly improved on Night 3 compared with Night 1.

Conclusions: Chronic intake of BZDs may be associated with poor sleep in this population. A progressive 15-day withdrawal did not avoid an immediate worsening of sleep parameters. But at the end of the protocol, SWS, delta count, and sleep quality were improved compared to those recorded during the chronic BZD intake, despite the lack of change in sleep efficiency.




JOURNAL: Arch Gen Psychiatry 2003 Jan;60(1):39-47
TITLE: Using chronic pain to predict depressive morbidity in the general population.
AUTHOR(S): Ohayon MM, Schatzberg AF.


BACKGROUND: Pain syndrome is thought to play a role in depression. This study assesses the prevalence of chronic (>or= 6 months' duration) painful physical conditions (CPPCs) (joint/articular, limb, or back pain, headaches, or gastrointestinal diseases) and their relationship with major depressive disorder.

METHODS: We conducted a cross-sectional telephone survey of a random sample of 18 980 subjects from 15 to 100 years old representative of the generalpopulations of the United Kingdom, Germany, Italy, Portugal, and Spain. Answers provided during telephone interviews using the Sleep-EVAL system were the main outcome measure. Interviews included questions about mental disorders and medical conditions. Data on painful physical conditions were obtained through questions about medical treatment, consultations, and/or hospitalizations for medical conditions and a list of 42 diseases.

RESULTS: Of all subjects interviewed, 17.1% reported having at least 1 CPPC (95% confidence interval [CI], 16.5%-17.6%). At least 1 depressive symptom (sadness, depression, hopelessness, loss of interest, or lack of pleasure) was present in 16.5% of subjects (95% CI, 16.0%-17.1%); 27.6% of these subjects had at least 1 CPPC. Major depressive disorder was diagnosed in 4.0% of subjects; 43.4% of these subjects had at least 1 CPPC, which was 4 times more often than in subjects without major depressive disorder (odds ratio [OR], 4.0; 95% CI, 3.5-4.7). In a logistic regression model, CPPC was strongly associated with major depressive disorder (OR: CPPC alone, 3.6; CPPC + nonpainful medical condition, 5.2); 24-hour presence of pain made an independent contribution to major depressive disorder diagnosis (OR, 1.6).

CONCLUSIONS: The presence of CPPCs increases the duration of depressive mood. Patients seeking consultation for a CPPC should be systematically evaluated for depression.




JOURNAL: J Psychiatr Res 2003 Jan-Feb;37(1):9-15
TITLE: Place of chronic insomnia in the course of depressive and anxiety disorders.
AUTHOR(S): Ohayon MM, Roth T.


BACKGROUND: Insomnia is frequent in the general population and is often related to a psychiatric illness. However, little is known about how the chronicity of insomnia affects this relation and how often subjects with chronic insomnia have antecedents of psychiatric disorders.

METHODS: A total of 14,915 subjects aged from 15 to 100 years representative of the general population of the United Kingdom, Germany, Italy, and Portugal were interviewed by telephone using the Sleep-EVAL system. The questionnaire assessed current psychiatric disorders according to the DSM-IV classification and a series of questions assessed the psychiatric history. Insomnia was considered as chronic when it lasted for 6 months or more.

RESULTS: The prevalence for insomnia accompanied with impaired daytime functioning was 19.1% and significantly increased with age. More than 90% of these subjects had a chronic insomnia. About 28% of subjects with insomnia had a current diagnosis of mental disorders and 25.6% had a psychiatric history. A DSM-IV insomnia disorder was found in 6.6% of the sample. Presence of severe insomnia, diagnosis of primary insomnia or insomnia related to a medical condition, and insomnia that lasted more than one year were predictors of a psychiatric history. In most cases of mood disorders, insomnia appeared before (> 40%) or in the same time (> 22%) than mood disorder symptoms. When anxiety disorders were involved, insomnia appeared mostly in the same time (>38%) or after (> 34%) the anxiety disorder.

CONCLUSIONS: The study shows that psychiatric history is closely related to the severity and chronicity of current insomnia. Moreover, chronic insomnia can be a residual symptom of a previous mental disorder and put these subjects to a higher risk of relapse.




JOURNAL: J Sleep Res 2002 Dec;11(4):339-46
TITLE: Insomnia and global sleep dissatisfaction in Finland.
AUTHOR(S): Ohayon MM, Partinen M.


The purpose of this study is to assess the prevalence of insomnia symptoms and diagnoses in the general population of Finland.

A total of 982 participants, aged 18 years or older and representative of the general population of Finland, were interviewed by telephone using the Sleep-EVAL system. The participation rate was 78%. The questionnaire included the assessment of sleep habits, insomnia symptomatology according to Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) and International Classification of Sleep Disorders (ICSD), associated and sleep/mental disorders and daytime consequences.

The overall prevalence of insomnia symptoms occurring at least three nights per week was 37.6%. Difficulty initiating sleep were mentioned by 11.9% of the sample, difficulty maintaining sleep by 31.6%, early morning awakenings by 11.0% and non-restorative sleep by 7.9% of the sample. Global dissatisfaction with sleep was found in 11.9% of the sample. Daytime consequences (fatigue, mood changes, cognitive difficulties or daytime sleepiness) were reported by 39.9% of participants with insomnia symptoms and 87.6% of those with sleep dissatisfaction. A deterioration of sleep in summer or winter was associated with more complaints of sleep dissatisfaction. Prevalence of any DSM-IV insomnia diagnosis was 11.7%. More specifically, DSM-IV diagnosis of primary insomnia had a prevalence of 1.6% and DSM-IV diagnosis of insomnia related to another mental disorder was at 2.1%. Insomnia was a symptom of another sleep disorder in about 16% of cases and of a mental disorder in about 17% of cases. As reported in other Nordic studies, sleep quality was worse in summer.

Insomnia symptomatology was common and was reported by more than a third of Finnish participants. Compared with other European countries studied with the same methodology (France, the UK, Germany, and Italy), the prevalence of DSM-IV insomnia diagnosis was 1.5 to two times higher in Finland.




JOURNAL: Am J Psychiatry 2002 Nov;159(11):1855-61
TITLE: Prevalence of depressive episodes with psychotic features in the general population.
AUTHOR(S): Ohayon MM, Schatzberg AF.


OBJECTIVE: The study evaluated the prevalence of major depressive episodes with psychotic features in the general population and sought to determine which depressive symptoms are most frequently associated with psychotic features.

METHOD: The sample was composed of 18,980 subjects aged 15-100 years who were representative of the general populations of the United Kingdom, Germany, Italy, Portugal, and Spain. The participants were interviewed by telephone by using the Sleep-EVAL system. The questionnaire included a series of questions about depressive disorders, delusions, and hallucinations.

RESULTS: Overall, 16.5% of the sample reported at least one depressive symptom at the time of the interview. Among these subjects, 12.5% had either delusions or hallucinations. More than 10% of the subjects who reported feelings of worthlessness or guilt and suicidal thoughts also had delusions. Feelings of worthlessness or guilt were also associated with high rates of hallucinations (9.7%) and combinations of hallucinations and delusions (4.5%). The current prevalence of major depressive episode with psychotic features was 0.4% (95% CI=0.35%-0.54%), and the prevalence of a current major depressive episode without psychotic features was 2.0% (95% CI=1.9%-2.1%), with higher rates in women than in men. In all, 18.5% of the subjects who fulfilled the criteria for a major depressive episode had psychotic features. Past consultations for treatment of depression were more common in depressed subjects with psychotic features than in depressed subjects with no psychotic features.

CONCLUSIONS: Major depressive episodes with psychotic features are relatively frequent in the general population, affecting four of 1,000 individuals. Feelings of worthlessness or guilt can be a good indicator of the presence of psychotic features.




JOURNAL: Encephale 2002 Sep-Oct;28(5 Pt 1):420-8
TITLE: [A connection between insomnia and psychiatric disorders in the French general population] [Article in French]
AUTHOR(S): Ohayon MM, Lemoine P.


Untreated insomnia often has repercussions on socio-professional or cognitive functioning of insomniacs. In industrialized countries, the prevalence of insomnia ranges between 10% and 48%, depending on the methodology and the measured time interval. However, few studies have examined the relationship between insomnia and mental disorder diagnoses.

This epidemiological study on insomnia complaints was conducted on 5 622 subjects representative of the non-institutionalized French population aged 15 years or over. Sixteen interviewers using the Sleep-EVAL expert system performed telephone interviews.

Insomnia complaints (defined as difficulty initiating or maintaining sleep, feeling unrefreshed at awakening accompanied by dissatisfaction with sleep quality or quantity, or use of sleep-promoting medication) were observed in 18.6% (95% confidence interval: 17.6% to 19.6%) of the sample. The median duration of insomnia complaints was five years. Regional variations in the prevalence of insomnia complaints were observed in France. In North 2 and Center 4 regions, the prevalence of insomnia complaints was higher compared to the rest of France with a relative risk of 1.4 (95% confidence interval: 1.1-1.6) time superior for the North region and 1.3 (95% CI: 1.0-1.6) for the Center 4 region. The lowest prevalence was registered in the Mediterranean area. In most regions, the prevalence of insomnia complaints was higher in women than in men with the exception of the South and West regions where the prevalence was similar. Subjects with insomnia complaints consulted more frequently compared to the rest of sample with an odds ratio of 3 to 1 [95% CI: 2.8 to 4.1]. Close to 20% of subjects were being treated for a physical disease at the time of the survey; subjects with insomnia complaints being twice more numerous (34.3%) than the rest of the sample (15.9%; p<0.001). To identify the main factors associated with insomnia complaints, socio-demographic and health variables were introduced in a multivariate model. Separated or divorced individuals (OR: 1.6); widowers (OR: 1.5); subjects aged between 45 and 65 years (OR: 1.4) or older than 65 (OR: 1.5); women (OR: 1.3); those with little or no education (OR: 1.4); and subjects living in the North region had higher reported insomnia complaints. Living in the East region (Mediterranean) was a protective factor (OR: 0.6). Furthermore, subjects with vascular diseases (OR: 2.0), musculo-skeletal diseases (OR: 2.0) or cardiac diseases (OR: 1.9) and those who had consulted a physician in the previous six months (OR: 2.7) had higher a probability of insomnia complaints. Subsequently, DSM IV insomnia diagnoses were examined in subjects who complained of insomnia. A diagnosis of primary insomnia was found in 7% of these subjects. A diagnosis of insomnia related to another mental disorder was found in 15.6% of insomnia complainers. A depressive disorder diagnosis was given in 10.8% of cases (mainly a major depressive disorder). This diagnosis was made more often among women and subjects of less than 65 years. An anxiety disorder diagnosis was given for 33.1% of insomnia complainers (an anxiety generalized disorder in about half the cases). About a quarter of insomnia complainers did not receive a diagnosis. This was the case more often for men and the subjects 65 years or older. If demographic and medical factors are relatively well documented at the epidemiological level, it is otherwise for psychiatric diagnosis associated with insomnia complaint. Very few studies in the general population have been done and still fewer of them have applied a positive and differential diagnosis process. In this study, we used the DSM IV classification to establish positive and differential diagnoses among subjects with insomnia complaints.

Compared to other epidemiological studies, our study is distinguished by several aspects: 1) insomnia complaint had a narrower definition. It did not suffice that the subject reported insomnia symptoms, it was also necessary that the subject said s/he was dissatisfied with her/hr/his sleep or that s/he took measures to improve it (medication or sleep hygiene). This choice was motivated essentially by the fact that it is difficult, from a point of clinical point of view, to consider that an individual has insomnia solely based on the presence of symptoms, that, appreciated by a clinician, would resemble insomnia without that they make problem for the subject. 2) Several sleep habits were systematically collected. The majority of epidemiological studies are not centered on sleep problems, with the consequence that results do not allow a global view of factors that are associated with insomnia. 3) The various diagnostic categories of insomnia as well as elements of the differential diagnosis were applied.

Thus, we can conclude that insomnia, as a diagnostic entity, including all its forms, is found in 5.6% of the French population. In the majority of cases, the insomnia complaint is part of the symptomatology of a mental disorder, mainly an anxiety disorder. This distinction is important since it helps the physician to determine therapeutic choices. To conclude, it is worthwhile to consider the number of insomnia complainers who had consulted a physician, mainly a general practitioner, in the six months prior to the study. This designates physicians as the first-line resource in the treatment and the prevention of sleep disorders.




JOURNAL: J Clin Psychiatry 2002 Sep;63(9):817-25
TITLE: Use of psychotropic medication in the general population of France, Germany, Italy, and the United Kingdom.
AUTHOR(S): Ohayon MM, Lader MH.


BACKGROUND: The use of psychotropic medications and its association with sleep and psychiatric and physical illnesses were studied in the general population.

METHOD: A cross-sectional telephone survey was carried out using the Sleep-EVAL knowledge-base system. A representative sample of the noninstitutionalized general populations of France, Germany, Italy, and the United Kingdom, aged 15 years or over, was interviewed (N = 18,679; participation rate: 78.8%; target population: 204,605,391 inhabitants). Questions were asked about psychotropic medication intake (name of medication, indication, dosage, duration of intake, prescriber), sociodemographics, physical illnesses, and DSM-IV mental disorders.

RESULTS: At the time of the interview, 6.4% of the subjects took a psychotropic medication. Anxiolytics were reported by 4.3% of the sample, hypnotics by 1.5%, antidepressants by 1.0%, and neuroleptics and other psychotropics by less than 1.0%. Hypnotics and anxiolytics were mostly used as a sleep disorder treatment. Antidepressants were taken appropriately for a depressive illness in only 44.1% of cases. Low doses of hypnotics and anxiolytics were found in about 10% of cases and low doses of antidepressants in 31.7% of cases. Subjects with a psychiatric disorder received a psychotropic treatment only infrequently (between 10% to 40.4%, depending on the disorder). All psychiatric disorders, including mood disorders, were treated mainly with an anxiolytic. A concomitant physical illness increased the likelihood of using a psychotropic treatment and was a strong predictor of adequate psychotropic dosage.

CONCLUSION: Psychiatric pathology and sleep disorders remained mostly untreated or inadequately managed in the general population. Depression is underdiagnosed by the physicians and is treated with antidepressant in only 7% of cases. By contrast, anxiolytics are extensively prescribed, especially in France and Italy. The co-occurrence of organic and psychiatry disorders increases the frequency of medical consultations and the likelihood of being given a prescription for the mental disorder.




JOURNAL: J Psychosom Res 2002 Jul;53(1):593-600
TITLE: Prevalence of insomnia and associated factors in South Korea.
AUTHOR(S): Ohayon MM, Hong SC.


INTRODUCTION: In Western countries, insomnia is associated with daytime impaired functioning, as well as physical and psychiatric illnesses. However, little information exists on insomnia in Asian countries. This study investigates the prevalence and correlates of insomnia in the general population of South Korea.

METHODS: A representative sample of the South Korean general population composed of 3719 noninstitutionalized individuals aged 15 years or older were interviewed by telephone using the Sleep-EVAL system. The participation rate was 91.4%. The interviews covered sleep habits, sleep symptomatology, physical and psychiatric illnesses. DSM-IV sleep and psychiatric disorder diagnoses were also assessed.

RESULTS: Insomnia symptoms occurring at least three nights per week were reported by 17.0% of the sample; difficulty initiating sleep (DIS) was mentioned by 4.0% of the sample, difficulty maintaining sleep (DMS) by 11.5%, early morning awakenings (EMA) by 1.8%, and nonrestorative sleep (NRS) by 4.7% of the sample. DSM-IV insomnia disorder diagnoses were found in 5% of the sample. Over 50% of subjects with insomnia symptoms reported important daytime consequences and another 20% reported mild or moderate consequences. However, the proportion of insomnia subjects seeking medical help for their sleep problems was very low (6.8%).

CONCLUSIONS: As in Western countries, insomnia is widespread in South Korea, affecting nearly one in five individuals. Many of them would benefit from medical help; however, few insomnia subjects are consulting for this problem. An educational effort is needed for both the general population and the physicians.




JOURNAL: J Psychosom Res 2002 Jul;53(1):577-83
TITLE: Prevalence and consequences of sleep disorders in a shift worker population.
AUTHOR(S): Ohayon MM, Lemoine P, Arnaud-Briant V, Dreyfus M.


INTRODUCTION: Irregular work schedules often results in a disruption of the normal circadian rhythm that can causes sleepiness when wakefulness is required and insomnia during the main sleep episode.

METHOD: Two physicians using the Sleep-EVAL system interviewed 817 staff members of a psychiatric hospital. The interviews were done during the working hours. In addition to a series of questions to evaluate sleep and mental disorders, the evaluation included a standard questionnaire assessing work conditions, work schedule and their consequences. Three work schedules were assessed: (1) fixed daytime schedule (n=442), (2) rotating daytime shifts (n=323) and (3) shift or nighttime work (n=52).

RESULTS: Subjects working on rotating daytime shifts were younger than the two other groups and had a higher proportion of women. Participants working on rotating daytime shifts reported more frequently than the fixed daytime schedule workers to have difficulty initiating sleep (20.1% vs. 12.0%). The sleep duration of shift or nighttime workers was shorter than that of the two other groups. Furthermore, subjects working rotating daytime schedule reported to have shorter sleep duration of about 20 min when they are assigned to the morning shift. Work-related accidents were two times more frequent among the rotating daytime workers (19.5%) compared with the fixed daytime schedule workers (8.8%) and the group of nighttime or shift workers (9.6%). Sick leaves in the previous 12 months were also more frequently reported in the rotating daytime schedule group (62.8%) as compared with the daytime group (38.5%, P<.001); 51.9% of nighttime or shift workers took sick leave.

CONCLUSIONS: Working on a rotating daytime shifts causes significant sleep disturbances. As consequences, these workers are more likely to feel sleepy at work and are more likely to have work-related accidents and sick leaves.




JOURNAL: J Psychosom Res 2002 Jul;53(1):547-54
TITLE: Prevalence of restless legs syndrome and periodic limb movement disorder in the general population.
AUTHOR(S): Ohayon MM, Roth T.


BACKGROUND: Periodic limb movement disorder (PLMD) and restless legs syndrome (RLS) are two sleep disorders characterized by abnormal leg movements and are responsible for deterioration in sleep quality. However, the prevalence of these disorders is not well known in the general population. This study aims to document the prevalence of RLS and PLMD in the general population and to identify factors associated with these conditions.

METHODS: Cross-sectional studies were performed in the UK, Germany, Italy, Portugal and Spain. Overall, 18,980 subjects aged 15 to 100 years old representative of the general population of these five European countries underwent telephone interviews with the Sleep-EVAL system. A section of the questionnaire assessed leg symptoms during sleep. The diagnoses of PLMD and RLS were based on the minimal criteria provided by the International Classification of Sleep Disorders.

RESULTS: The prevalence of PLMD was 3.9% and RLS was 5.5%. RLS and PLMD were higher in women than in men. The prevalence of RLS significantly increased with age. In multivariate models, being a woman, the presence of musculoskeletal disease, heart disease, obstructive sleep apnea syndrome, cataplexy, doing physical activities close to bedtime and the presence of a mental disorder were significantly associated with both disorders. Factors specific to PLMD were: being a shift or night worker, snoring, daily coffee intake, use of hypnotics and stress. Factors solely associated with RLS were: advanced age, obesity, hypertension, loud snoring, drinking at least three alcoholic beverages per day, smoking more than 20 cigarettes per day and use of SSRI.

CONCLUSIONS: PLMD and RLS are prevalent in the general population. Both conditions are associated with several physical and mental disorders and may negatively impact sleep. Greater recognition of these sleep disorders is needed.




JOURNAL: Encephale 2002 May-Jun;28(3 Pt 1):217-26
TITLE: [Methodology of a study on insomnia in the general population] [Article in French]
AUTHOR(S): Ohayon MM.


The study of sleep disorders in the general population involves several methodological issues that need to be defined prior to proceeding to the epidemiological study. The rigor of the methodology is an important issue since it will determine the reliability of the data gathered. This paper describes the methodology used in an epidemiological study performed in the French general population using telephone interviews with the help of Sleep-EVAL, an expert system designed for this purpose.

The study aimed to investigate the prevalence of insomnia disorders according to the DSM IV classification and the use of psychotropic medications in the general population.

The methodological choices for this study were based on several considerations. First, the sample had to be representative of the French population. Second, the study had to be conducted in the shortest period of time. Third, the interviews had to be conducted with respect to a strict standardization and fourth, the realization costs had to be minimal for a maximum of data collected.

The telephone interview procedure was chosen over postal and face-to-face interviews because it offered the possibility of conducting all the interviews from the same site. Supervision was easier. It also offered an absolute control in the application of the selection procedure. To draw the sample, a two-stage procedure was adopted. At the first stage, we pulled a random series of telephone numbers in each Nielsen region with respect to the size of the settlement. At the second stage, during the initial telephone contact, a household member was chosen using the Kish selection procedure. This method is based on the utilization of eight tables of selection that allows for the choice of the person to interview in a given household and keeps the representativeness of the sample. This technique is little used in telephone surveys because of its burden and its intrusive nature: the interviewer must collect the age and gender of all eligible subjects, to classify men from the oldest to youngest and then to classify women. However, it is the most rigorous selection method for epidemiological surveys. To reduce the refusal rates and to alleviate the work of interviewers, the Kish method was implanted in the computer software used for this study.

For this study, the exclusion criteria were minimal. Only individuals younger than 15 years of age, those with a speech or hearing impairment and those who were too ill to perform the interview were not included. Subjects who refused to participate, those who hung up without speaking to the interviewer and those who hung up before completing at least half of the interview were tabulated as refusal.

The participation rate was calculated by dividing the number of completed interviews by the number of eligible participants (completed interviews, refusals and telephone numbers where the interviewer was unable to determine if the individuals met an exclusion criterion). In this study, the participation rate was 80.8% (5 622 completed interviews/6 966 eligible households).

The diagnostic tool used for this study was the Sleep-EVAL system, an expert system designed to conduct epidemiological studies in the general population. It is a level 2, non-monotonic system endowed with a causal reasoning able to provide sleep and mental disorders diagnoses according to the DSM IV classification for this study. Subsequent versions of Sleep-EVAL also included the International Classification of Sleep Disorders. System symbolic representation of the classifications was put in a compiled knowledge base. This knowledge base was read and interpreted by the inference engine at the beginning of the interview. During the interview, this interpretation changed as a function of the answers provided by the interviewee and by deductions made from the analysis of information the system already knew. All interviews began with a standard questionnaire about sociodemographic information and sleep habits. From these first answers, the Sleep-EVAL system emitted a series of diagnostic hypotheses that were confirmed or rejected with supplementary questions. The interview ended once all diagnostic possibilities were exhausted.

The validity of the Sleep-EVAL system was demonstrated in different studies performed in sleep disorders clinics. There were several advantages in using such a tool to conduct epidemiological surveys. No special skills from the interviewers nor specific knowledge of sleep and mental disorders were required. All the questions were chosen and formulated by the Sleep-EVAL system. The interviewer had simply to read the questions as they appeared on the monitor screen and enter the interviewee's responses by clicking the appropriate answer or typing it on the keyboard. Missing answers were non-existent because there was no possibility of skipping a question or entering inconsistent answers. It also ensured the uniformity of the interviews. Furthermore, it allowed the exploration of infrequent diagnoses.

In summary, the methodology used for this study allowed for the investigation of the sleep pathology of the French population in a short period of time: only three months were necessary to complete the 5 622 interviews. The use of a computerized tool greatly facilitated the training of the interviewers and also their work. Furthermore, it ensured a standardized administration of the interviews and the exploration of a broad range of disorders that could hardly be realized with traditional paper-pencil questionnaires.




JOURNAL: Neurology 2002 Jun 25;58(12):1826-33
TITLE: Prevalence of narcolepsy symptomatology and diagnosis in the European general population.
AUTHOR(S): Ohayon MM, Priest RG, Zulley J, Smirne S, Paiva T.


OBJECTIVE: To determine the prevalence of narcolepsy in the general population of five European countries (target population 205,890,882 inhabitants).

METHODS: Overall, 18,980 randomly selected subjects were interviewed (participation rate 80.4%). These subjects were representative of the general population of the UK, Germany, Italy, Portugal, and Spain. They were interviewed by telephone using the Sleep-EVAL expert system, which provided narcolepsy diagnosis according to the International Classification of Sleep Disorders (ICSD).

RESULTS: Excessive daytime sleepiness was reported by 15% of the sample, with a higher prevalence in the UK and Germany. Napping two times or more in the same day was reported by 1.6% of the sample, with a significantly higher rate in Germany. Cataplexy (episodes of loss of muscle function related to a strong emotion), a cardinal symptom of narcolepsy, was found in 1.6% of the sample. An ICSD narcolepsy diagnosis was found in 0.047% of the sample: The narcolepsy was severe for 0.026% of the sample and moderate in 0.021%.

CONCLUSION: This is the first epidemiologic study that estimates the prevalence of narcolepsy in the general population of these five European countries. The disorder affects 47 individuals/100,000 inhabitants.




JOURNAL: Sleep Med. 2002 Mar;3(2):115-20
TITLE: Prevalence and consequences of insomnia disorders in the general population of Italy.
AUTHOR(S): Ohayon MM, Smirne S.


OBJECTIVES: To assess the prevalence of insomnia disorders using DSM-IV classification, and the consequences of insomnia in the Italian general population.

METHODS: A representative sample of the Italian general population composed of 3970 individuals aged 15 years or older were interviewed by telephone using the Sleep-EVAL system (participation rate: 89.4%). Participants were interviewed about their sleep habits and sleep disorders. DSM-IV classification was used by Sleep-EVAL to determine the sleep disorder diagnosis.

RESULTS: Insomnia symptoms were reported by 27.6% of the sample. Sleep dissatisfaction was found in 10.1% and insomnia disorder diagnoses in 7% of the sample. The use of sleep-enhancing medication was reported by 5.7% of the sample. Most of these subjects were using anxiolytics. Dissatisfaction with sleep was associated with daytime sleepiness. Middle-aged drivers dissatisfied with their sleep were three times more likely to have had a road accident in the previous year compared to other drivers. However, fewer than 30% of subjects dissatisfied with their sleep or with an insomnia disorder diagnosis had consulted a physician about their sleep problem.

CONCLUSIONS: As in other European and non-European countries, insomnia is widespread in Italy. The consequences are important. Appropriate recognition and treatment of insomnia should be part of an educational program for general practitioners everywhere.




JOURNAL: Arch Intern Med 2002 Jan 28;162(2):201-8
TITLE: Daytime sleepiness and cognitive impairment in the elderly population.
AUTHOR(S): Ohayon MM, Vecchierini MF.


BACKGROUND: Recent findings suggest that there may be a relationship between excessive daytime sleepiness (EDS) and cognitive deficits. This study aims to determine to what extent EDS is predictive of cognitive impairment in an elderly population.

METHODS: A total of 1026 individuals 60 years or older representative of the general population living in the metropolitan area of Paris, France, were interviewed by telephone using the Sleep-EVAL expert system. To find these individuals, 7010 randomly selected households were called: 1269 had at least 1 household member in this age range (participation rate, 80.9%). In addition to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and International Classification of Sleep Disorders diagnoses, the system administered to participants the Psychological General Well-being Schedule, the Cognitive Difficulties Scale (MacNair-R), and an independent living scale.

RESULTS: Excessive daytime sleepiness was reported by 13.6% of the sample, with no significant difference among age groups. Compared with nonsleepy participants, those with EDS were at increased risk of cognitive impairment on all the dimensions of the MacNair-R scale after controlling for age, sex, physical activity, occupation, organic diseases, use of sleep or anxiety medication, sleep duration, and psychological well-being. The odd ratios were 2.1 for attention-concentration deficits, 1.7 for praxis, 2.0 for delayed recall, 2.5 for difficulties in orientation for persons, 2.2 for difficulties in temporal orientation, and 1.8 for prospective memory.

CONCLUSIONS: Among elderly individuals in the general population, EDS is an important risk factor for cognitive impairment. A complaint of EDS by an elderly patient should signal the possibility of an underlying cognitive impairment in need of evaluation.




JOURNAL: Sleep 2001 Dec 15;24(8):920-5
TITLE: Comparability of sleep disorders diagnoses using DSM-IV and ICSD classifications with adolescents.
AUTHOR(S): Ohayon MM, Roberts RE.


STUDY OBJECTIVES: The use of diagnostic classifications to define sleep disorders is still unusual in epidemiological studies assessing the prevalence of sleep disorders in an adolescent population.

DESIGN: Cross-sectional study. Representative samples of general populations in United Kingdom, Germany and Italy were selected and interviewed by telephone about their sleep habits, sleep and mental disorder diagnoses. Overall, 724 adolescents ages 15-18 years and 1447 young adults ages 19 to 24 years were interviewed. ICSD-90 and DSM-IV diagnoses provided by the Sleep-EVAL expert system were used for the comparisons.

SETTING: N/A. PARTICIPANTS: N/A. INTERVENTIONS: N/A.

MEASUREMENTS AND RESULTS: 8% of the adolescents and 12.6% of the young adults had ICSD dyssomnia or sleep disturbances associated with a mental disorder. According to the DSM-IV classification, 5.7% of the adolescents and 8.1% of the young adults had a dyssomnia diagnosis. The comparison between the two classifications show that 73.2% of adolescents and young adults with a DSM-IV dyssomnia diagnosis also had similar ICSD diagnosis. The reverse comparison, ICSD vs. DSM-IV, shows that 39.8% of the subjects with an ICSD diagnosis had a DSM-IV diagnosis. DSM-IV primary insomnia was the most frequent diagnosis. Subjects with such a diagnosis were found in about 10 different ICSD diagnoses, mainly inadequate sleep hygiene, psychophysiological or idiopathic insomnia and insufficient sleep syndrome.

CONCLUSIONS: ICSD-90 classification provided higher prevalence of sleep disorder diagnoses than the DSM-IV classification. In adolescents and young adults, DSM-IV primary insomnia is two times more often associated with ICSD inadequate sleep hygiene than with ICSD psychophysiological or idiopathic insomnia.




JOURNAL: J Psychosom Res 2001 Dec;51(6):745-55
TITLE: What are the contributing factors for insomnia in the general population?
AUTHOR(S): Ohayon MM, Roth T.


Lack of a systematic assessment of insomnia has led to large variations in its reported prevalence in the general population.

This study aims to provide new guidelines to assess insomnia prevalence. A cross-sectional telephone survey using the Sleep-EVAL system was done with 24,600 general population-based subjects 15 years and older representative of general populations (France, the UK, Germany, Italy, Portugal, and Spain) consisting of 251,405,391 inhabitants. The overall participation rate was 81.0%.

Within the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) symptomatology for insomnia, 27.2% (95% confidence interval: 26.6-27.8%) of the sample reported difficulty initiating sleep (DIS) (10.1%) or maintaining sleep (DMS) (disrupted sleep (DS): 18.0%; early morning awakening (EMA): 10.9%) or nonrestorative sleep (NRS) (8.9%) at least three times per week; 48.5% of them were concomitantly suffering of a DSM-IV sleep/mental disorder. A factor analysis identified several variables strongly related to each of the major factors of insomnia allowing: (1) The narrowing of the definition of insomnia: the prevalence of insomnia decreased to 16.8% with 64.5% of insomnia subjects having a DSM-IV sleep/mental disorder; (2) The identification of a sleep-deprived (voluntary or not) group without insomnia symptoms, representing 2.1% (1.9-2.3%) of the sample. Interestingly, the latter group closely matched the definition of insufficient sleep syndrome as described by the International Classification of Sleep Disorders (ICSD).

Using more delineated criteria to assess insomnia increases the recognition of subjects complaining about sleep. Classifications should be amended to improve the correct identification of insomnia. Sleep-deprived subjects should also not be neglected.




JOURNAL: Sleep 2001 Nov 1;24(7):780-7
TITLE: Correlates of global sleep dissatisfaction in the German population.
AUTHOR(S): Ohayon MM, Zulley J.


STUDY OBJECTIVES: Global sleep dissatisfaction (GSD) is not part of the habitual insomnia symptoms in epidemiological studies. Furthermore, none of these studies has examined the relative importance of the various factors correlated to sleep dissatisfaction. This study aims to examine the links between GSD and insomnia and to find the factors contributing to GSD.

DESIGN: A cross-sectional telephone survey was conducted in Germany (66 million inhabitants 15 years of age or older) with a representative sample of 4,115 subjects aged 15 years or older. Interviewers used the Sleep-EVAL system. The questionnaire covered several topics that were grouped into six classes of variables identified as potential factors associated with sleep dissatisfaction: sociodemographic descriptors, environmental factors, life habits, health status, psychological factors, sleep/wake factors.

SETTING: N/A.

PARTICIPANTS: A representative sample of 4,115 subjects aged 15 years or older

INTERVENTIONS: N/A.

MEASUREMENTS AND RESULTS: Overall, 7% of the subjects reported being GSD; 95.5% of them had at least one insomnia symptom. The duration of insomnia symptom(s) was 20 months longer in GSD subjects compared to insomnia subjects without GSD. The prevalence of GSD was higher in women than in men and increased with age. The most significant predictive factors for GSD were: 1) for sleep/wake schedule variables: night sleep duration less than 6 hours (OR: 4.0 and over) and sleep latency greater than 30 minutes. 2) for sociodemographic variables: age between 65 and 74 (OR: 6.7) 3) for health variables: Upper airway disease (OR: 7.1); 4) for mental health variables: anxiety symptoms (OR: 3.0); 5) for environmental factors: too hot bedroom (OR=2.5) 6) for life habit factors: the need of a particular object in order to fall asleep (OR: 2.4).

CONCLUSIONS: This study confirms that GSD is a better indicator of an underlying pathology than the classical insomnia symptoms alone: compared to insomniac subjects without GSD, subjects with GSD were two times more likely to report excessive daytime sleepiness, and eight times more likely to have a diagnosis of sleep or mental disorder. Furthermore, in car drivers, road accidents in the previous year were two times more frequent with GSD drivers as compared to insomnia drivers without GSD. Subjects with GSD were more than 10 times more likely to seek help for their sleep problems and five times more likely to use a sleep medication than insomnia subjects without GSD.




JOURNAL: J Am Geriatr Soc 2001 Apr;49(4):360-6
TITLE: How age and daytime activities are related to insomnia in the general population: consequences for older people.
AUTHOR(S): Ohayon MM, Zulley J, Guilleminault C, Smirne S, Priest RG.


OBJECTIVES: To determine the role of activity status and social life satisfaction on the report of insomnia symptoms and sleeping habits.

DESIGN: Cross-sectional telephone survey using the Sleep-EVAL knowledge base system.

SETTING: Representative samples of three general populations (United Kingdom, Germany, and Italy).

PARTICIPANTS: 13,057 subjects age 15 and older: 4,972 in the United Kingdom, 4,115 in Germany, and 3,970 in Italy. These subjects were representative of 160 million inhabitants.

MEASUREMENTS: Clinical questionnaire on insomnia and investigation of associated pathologies (psychiatric and neurological disorders).

RESULTS: Insomnia symptoms were reported by more than one-third of the population age 65 and older. Multivariate models showed that age was not a predictive factor of insomnia symptoms when controlling for activity status and social life satisfaction. The level of activity and social interactions had no influence on napping, but age was found to have a significant positive effect on napping.

CONCLUSIONS: These results indicate that the aging process per se is not responsible for the increase of insomnia often reported in older people. Instead, inactivity, dissatisfaction with social life, and the presence of organic diseases and mental disorders were the best predictors of insomnia, age being insignificant. Healthy older people (i.e., without organic or mental pathologies) have a prevalence of insomnia symptoms similar to that observed in younger people. Moreover, being active and satisfied with social life are protective factors against insomnia at any age.




JOURNAL: Psychiatry Res 2000 Dec 27;97(2-3):153-64
TITLE: Prevalence of hallucinations and their pathological associations in the general population.
AUTHOR(S): Ohayon MM.


Hallucinations are perceptual phenomena involved in many fields of pathology. Although clinically widely explored, studies in the general population of these phenomena are scant.

This issue was investigated using representative samples of the non-institutionalized general population of the United Kingdom, Germany and Italy aged 15 years or over (N=13,057). These surveys were conducted by telephone and explored mental disorders and hallucinations (visual, auditory, olfactory, haptic and gustatory hallucinations, out-of-body experiences, hypnagogic and hypnopompic hallucinations).

Overall, 38.7% of the sample reported hallucinatory experiences (19.6% less than once in a month; 6.4% monthly; 2.7% once a week; and 2.4% more than once a week). These hallucinations occurred, (1) At sleep onset (hypnagogic hallucinations 24.8%) and/or upon awakening (hypnopompic hallucinations 6.6%), without relationship to a specific pathology in more than half of the cases; frightening hallucinations were more often the expression of sleep or mental disorders such as narcolepsy, OSAS or anxiety disorders. (2) During the daytime and reported by 27% of the sample: visual (prevalence of 3.2%) and auditory (0.6%) hallucinations were strongly related to a psychotic pathology (respective OR of 6.6 and 5.1 with a conservative estimate of the lifetime prevalence of psychotic disorders in this sample of 0.5%); and to anxiety (respective OR of 5.0 and 9.1). Haptic hallucinations were reported by 3.1% with current use of drugs as the highest risk factor (OR=9.8).

In conclusion, the prevalence of hallucinations in the general population is not negligible. Daytime visual and auditory hallucinations are associated with a greater risk of psychiatric disorders. The other daytime sensory hallucinations are more related to an organic or a toxic disorder.




JOURNAL: Chest 2001 Jan;119(1):53-61
TITLE: Risk factors for sleep bruxism in the general population.
AUTHOR(S): Ohayon MM, Li KK, Guilleminault C.


OBJECTIVE: Sleep bruxism can have a significant effect on the patient's quality of life. It may also be associated with a number of disorders. However, little is known about the epidemiology of sleep bruxism and its risk factors in the general population.

DESIGN: Cross-sectional telephone survey using the Sleep-EVAL knowledge based system. SETTINGS: Representative samples of three general populations (United Kingdom, Germany, and Italy) consisting of 158 million inhabitants.

PARTICIPANTS: Thirteen thousand fifty-seven subjects aged > or = 15 years (United Kingdom, 4,972 subjects; Germany, 4,115 subjects; and Italy, 3,970 subjects).

INTERVENTION: None.

MEASUREMENTS: Clinical questionnaire on bruxism (using the International Classification of Sleep Disorders [ICSD] minimal set of criteria) with an investigation of associated pathologies (ie, sleep, breathing disorders, and psychiatric and neurologic pathologies).

RESULTS: Grinding of teeth during sleep occurring at least weekly was reported by 8.2% of the subjects, and significant consequences from teeth grinding during sleep (ie, muscular discomfort on awakening, disturbing tooth grinding, or necessity of dental work) were found in half of these subjects. Moreover, 4.4% of the population fulfilled the criteria of ICSD sleep bruxism diagnosis. Finally, subjects with obstructive sleep apnea syndrome (odds ratio [OR], 1.8), loud snorers (OR, 1.4), subjects with moderate daytime sleepiness (OR, 1.3), heavy alcohol drinkers (OR, 1.8), caffeine drinkers (OR, 1.4), smokers (OR, 1.3), subjects with a highly stressful life (OR, 1.3), and those with anxiety (OR, 1.3) are at higher risk of reporting sleep bruxism.

CONCLUSIONS: Sleep bruxism is common in the general population and represents the third most frequent parasomnia. It has numerous consequences, which are not limited to dental or muscular problems. Among the associated risk factors, patients with anxiety and sleep-disordered breathing have a higher number of risk factors for sleep bruxism, and this must raise concerns about the future of these individuals. An educational effort to raise the awareness of dentists and physicians about this pathology is necessary.




JOURNAL: J Am Acad Child Adolesc Psychiatry 2000 Dec;39(12):1549-56
TITLE: Prevalence and patterns of problematic sleep among older adolescents.
AUTHOR(S): Ohayon MM, Roberts RE, Zulley J, Smirne S, Priest RG.


OBJECTIVE: Despite many constraints on time schedules among teenagers, epidemiological data on sleep complaints in adolescence remain limited and are nonexistent for sleep disorders. This study provides additional data on sleep habits and DSM-IV sleep disorders in late adolescence.

METHOD: A representative sample of 1,125 adolescents aged 15 to 18 years was interviewed by telephone using the Sleep-EVAL system. These adolescents came from 4 European countries: France, Great Britain, Germany, and Italy. Information was collected about sociodemographic characteristics, sleep/wake schedule, sleep habits, and sleep disorders and was compared with information from 2,169 young adults (19-24 years of age).

RESULTS: Compared with young adults, adolescents presented with a distinct sleep/wake schedule: they went to sleep earlier, they woke up later, and they slept longer than young adults did. On weekends and days off, they also slept more than young adults did. However, the prevalence rates of sleep symptoms and sleep disorders were comparable in both groups. Approximately 25% reported insomnia symptoms and approximately 4% had a DSM-IV insomnia disorder. Fewer than 0.5% had a circadian rhythm disorder.

CONCLUSIONS: Prevalence of insomnia disorders is lower in the adolescent population than in middle-aged or elderly adults. However, a rate of 4% in this young population is important given their young age and the consequences for daytime functioning.




JOURNAL: Compr Psychiatry 2000 Nov-Dec;41(6):469-78
TITLE: Sleep disturbances and psychiatric disorders associated with posttraumatic stress disorder in the general population.
AUTHOR(S): Ohayon MM, Shapiro CM.


The aim of the study was to assess sleep disturbances in subjects with posttraumatic stress disorder (PTSD) from an urban general population and to identify associated psychiatric disorders in these subjects.

The study was performed with a representative sample of 1,832 respondents aged 15 to 90 years living in the Metropolitan Toronto area who were surveyed by telephone (participation rate, 72.8%). Interviewers used Sleep-EVAL, an expert system specifically designed to conduct epidemiologic studies of sleep and mental disorders in the general population.

Overall, 11.6% of the sample reported having experienced a traumatic event, with no difference in the proportion of men and women. Approximately 2% (1.8%) of the entire sample were diagnosed by the system as having PTSD at the time of interview. The rate was higher for women (2.6%) than for men (0.9%), which translated into an odds ratio (OR) of 2.8 (95% confidence interval [CI], 1.3 to 6.1). PTSD was strongly associated with other mental disorders: 75.7% of respondents with PTSD received at least one other diagnosis. Most concurrent disorders (80.7%) appeared after exposure to the traumatic event. Sleep disturbances also affected about 70% of the PTSD subjects. Violent or injurious behaviors during sleep, sleep paralysis, sleep talking, and hypnagogic and hypnopompic hallucinations were more frequently reported in respondents with PTSD.

Considering the relatively high prevalence of PTSD and its important comorbidity with other sleep and psychiatric disorders, an assessment of the history of traumatic events should be part of a clinician's routine inquiry in order to limit chronicity and maladjustment following a traumatic exposure. Moreover, complaints of rapid eye movement (REM)-related sleep symptoms could be an indication of an underlying problem stemming from PTSD.




JOURNAL: J Psychosom Res 2000 Jun;48(6):593-601
TITLE: Is sleep-disordered breathing an independent risk factor for hypertension in the general population (13,057 subjects)?
AUTHOR(S): Ohayon MM, Guilleminault C, Priest RG, Zulley J, Smirne S.


OBJECTIVES Sleep-disordered breathing has been hypothesized to have a close relationship with hypertension but previous studies have reported mixed results. This is an important health issue that requires further clarification because of the potential impact on the prevention and control of hypertension.

METHODS: The relationship between hypertension and three forms of sleep-disordered breathing (chronic snoring, breathing pauses and obstructive sleep apnea syndrome (OSAS)) was assessed using representative samples of the non-institutionalized population of the UK, Germany and Italy (159 million inhabitants). The samples were comprised of 13,057 individuals aged 15-100 years who were interviewed about their sleeping habits and their sleep symptoms over the telephone using the Sleep-EVAL system. RESULTS: OSAS was found in 1.9% (95% CI: 1.2% to 2.3%) of the UK sample, 1.8% (95% CI: 1.4% to 2.2%) of the German sample and 1.1% (95% CI: 0.8% to 1.4%) of the Italian sample. OSAS was an independent risk factor (odds ratio (OR): 9.7) for hypertension after controlling for possible confounding effects of age, gender, obesity, smoking, alcohol consumption, life stress, and, heart and renal disease.

CONCLUSIONS: Results from three of the most populated countries in Western Europe indicate that OSAS is an independent risk factor for hypertension. Snoring and breathing pauses during sleep appeared to be non-significant predictive factors.




JOURNAL: J Nerv Ment Dis 2000 Jun;188(6):340-8
TITLE: The place of confusional arousals in sleep and mental disorders: findings in a general population sample of 13,057 subjects.
AUTHOR(S): Ohayon MM, Priest RG, Zulley J, Smirne S.


Confusional arousals, or sleep drunkenness, occur upon awakening and remain unstudied in the general population.

We selected a representative sample from the United Kingdom, Germany, and Italy (N = 13,057) and conducted telephone interviews.

Confusional arousals were reported by 2.9% of the sample: 1% (95% confidence interval: .8 to 1.2%) of the sample also presented with memory deficits (53.9%), disorientation in time and/or space (71%), or slow mentation and speech (54.4%), and 1.9% (1.7% to 2.1%) reported confusional arousals without associated features. Younger subjects (< 35 years) and shift or night workers were at higher risk of reporting confusional arousals. These arousals were strongly associated with the presence of a mental disorder with odds ratios ranging from 2.4 to 13.5. Bipolar and anxiety disorders were the most frequently associated mental disorders. Furthermore, subjects with Obstructive Sleep Apnea Syndrome (OSAS), hypnagogic or hypnopompic hallucinations, violent or injurious behaviors, insomnia, and hypersomnia are more likely to suffer from confusional arousals.

Confusional arousals appears to occur quite frequently in the general population, affecting mostly younger subjects regardless of their gender. Physicians should be aware of the frequent associations between confusional arousals, mental disorders, and OSAS. Furthermore, the high occurrence of confusional arousals in shift or night workers may increase the likelihood of inappropriate response by employees sleeping at work.




JOURNAL: Can J Psychiatry 2000 Mar;45(2):166-72
TITLE: Differentiating DSM-IV anxiety and depressive disorders in the general population: comorbidity and treatment consequences.
AUTHOR(S): Ohayon MM, Shapiro CM, Kennedy SH.


OBJECTIVE: To attempt, for the first time, to apply a positive and differential diagnosis process in the general population during interviews using DSM-IV classification to ascertain the profile and occurrence of concomitant mental disorders.

METHOD: A representative sample of 1832 individuals aged 15 years or older living in the metropolitan area of Toronto were interviewed by means of telephone interviews. The participation rate was 72.8%. RESULTS: Overall, 13.2% (n = 242) of the sample had either a mood disorder (n = 127; 6.9%) or an anxiety disorder (n = 170; 9.3%) at the time of their interview. The prevalence was higher among women (16.5%) than among men (9.7%), with an odds ratio of 1.8. The comorbidity of mood and anxiety disorders was found in 3% (n = 55) of the sample. Less than one-third of respondents with a mood and/or anxiety disorder were being treated by a physician for a mental disorder. However, these individuals were greater consumers of health care services. Most of them consulted a physician an average of 5 times in the past year. Individuals on medication diagnosed with a mood and an anxiety disorder consulted a physician an average of 12 times in the past year. Only 13% of them were treated with antidepressants and under 9% with anxiolytics.

CONCLUSIONS: More than 70% of subjects with a mood disorder also complained of insomnia. With the differential process, 12% of the subjects manifesting a full-fledged anxiety disorder were diagnosed with only a mood disorder because the anxiety occurred only in the course of the mood disorder. About two-thirds of the subjects diagnosed in this study were undiagnosed and untreated by their physician.




JOURNAL: J Psychosom Res 1999 Oct;47(4):359-68
TITLE: Are prescribed medications effective in the treatment of insomnia complaints?
AUTHOR(S): Ohayon MM, Caulet M, Arbus L, Billard M, Coquerel A, Guieu JD, Kullmann B, Loffont F, Lemoine P, Paty J, Pechadre JC, Vecchierini MF, Vespignani H.


Although frequently investigated in the general population, the epidemiology of insomnia complaints and their treatment have received little attention in general practice.

This study recruited patients > or =15 years of age, consecutively, from 127 general practitioners in France. The physicians collected data from 11,810 of their patients, of whom 55.5% were women. Insomnia complaints were reported by 26.2% (25.4% to 27%) of the sample and use of sleep-promoting medication by 10.1% (9.7% to 10.7%). About 47% of the prescribed drugs used were anxiolytics and 45% hypnotics. Most consumers took sleep-enhancing drugs on a daily and long-term basis and most reported that the medication improved their quality of sleep. However, few distinctions emerged between elderly drug-taking insomniacs and elderly nontreated insomniacs with respect to the various dimensions of sleep.

Results underscore the persistent general tendency among French general practitioners to overprescribe anxiolytics for the treatment of insomnia complaints and that they do so on a long-term basis, despite the findings of numerous studies showing that benzodiazepines are ineffective in the treatment of sleep complaints over the long term.




JOURNAL: J Psychosom Res 1999 Oct;47(4):297-311
TITLE: Improving decisionmaking processes with the fuzzy logic approach in the epidemiology of sleep disorders.
AUTHOR(S): Ohayon MM.


Epidemiological studies can provide information not only on specific diagnostic entities but also on their underlying symptomatic constellations.

For this purpose, an expert system was developed for the assessment of sleep disorders and endowed with the fuzzy logic capabilities necessary to determine the degree to which a given symptom corresponds to a specific diagnosis.

Uncertainty is inherent in fields such as sleep medicine and psychiatry, and becomes evident in clinical practice at the stages of data collection and diagnostic formulation, when the clinician must determine whether a symptom is present and must choose from several diagnostic possibilities. The process involves a considerable degree of subjectivity on the part of the patient in trying to describe his or her symptoms, and of the clinician whose final diagnosis will depend on his or her clinical experience and interpretation of what is normal and what is pathological. Inferential models of the probabilistic or fuzzy logic type take into account such uncertainty.

The Sleep-Eval system has been used in epidemiological and clinical studies involving 34,044 interviews collected by close to 300 interviewers. The diagnostic potential of these models is illustrated using data collected in an epidemiological study of the noninstitutionalized general population of Italy and underlines the advantages and limits of the binary, bayesian, and fuzzy logic methods and analyses.




JOURNAL: Sleep 1999 Nov 1;22(7):925-30
TITLE: Validation of the sleep-EVAL system against clinical assessments of sleep disorders and polysomnographic data.
AUTHOR(S): Ohayon MM, Guilleminault C, Zulley J, Palombini L, Raab H.


OBJECTIVES: To validate the Sleep-EVAL expert system, a computerized tool designed for the assessment of sleep disorders, against polysomnographic data and clinical assessments by sleep specialists.

DESIGN: Patients were interviewed twice, once by a physician using Sleep-EVAL and again by a sleep specialist. Polysomnographic data were also recorded to ascertain diagnoses. Agreement between diagnoses generated by Sleep-EVAL and those formulated by sleep specialists was determined via the kappa statistic.

SETTINGS: Sleep disorder centers at Stanford University (USA) and Regensburg University (Germany).

PATIENTS: 105 patients aged 18 years or over.

INTERVENTIONS: NA.

RESULTS: Sleep-EVAL made an average of 1.32 diagnoses per patient, compared with 0.93 for the sleep specialists. Overall agreement on any sleep-breathing disorder was 96.9% (Kappa .94). More than half of the patients were diagnosed with obstructive sleep apnea syndrome (OSAS); the agreement rate for this specific diagnosis was 96.7% (Kappa .93).

CONCLUSIONS: The findings indicate that the Sleep-EVAL system is a valid instrument for the recognition of major sleep disorders, particularly insomnia and OSAS.




JOURNAL: J Clin Psychiatry 1999 Apr;60(4):268-76; quiz 277
TITLE: Night terrors, sleepwalking, and confusional arousals in the general population: their frequency and relationship to other sleep and mental disorders.
AUTHOR(S): Ohayon MM, Guilleminault C, Priest RG.


BACKGROUND: Arousal parasomnias (night terrors, sleepwalking, and confusional arousals) have seldom been investigated in the adult general population. Clinical studies of parasomnias, however, show that these disorders may be indicators of underlying mental disorders and may have serious consequences.

METHOD: A representative sample of the United Kingdom population (N = 4972) was interviewed by telephone with the Sleep-EVAL system.

RESULTS: Night terrors were reported by 2.2% (95% CI = 1.8% to 2.6%) of the sample, sleepwalking by 2.0% (1.6% to 2.4%), and confusional arousals by 4.2% (3.6% to 4.8%). The rate of these 3 parasomnias decreased significantly with age, but no gender difference was observed. Multivariate models identified the following independent factors as associated with confusional arousals (odds ratio [OR]): age of 15-24 years (OR = 4.1), shift work (OR = 2.1), hypnagogic hallucinations (OR = 3.3), deep sleep (OR = 1.6), daytime sleepiness (OR = 1.9), sleep talking (OR = 1.7), daily smoking (OR = 1.7), adjustment disorder (OR = 3.1), and bipolar disorder (OR = 13.0). Factors associated with night terrors were subjective sense of choking or blocked breathing at night (OR = 5.1), obstructive sleep apnea syndrome (OR = 4.1), alcohol consumption at bedtime (OR = 3.9), violent or injury-causing behaviors during sleep (OR = 3.2), hypnagogic hallucinations (OR = 2.2), and nightmares at least 1 night per month (OR = 4.0). Factors associated with sleepwalking were age of 15-24 years (OR = 5.2), subjective sense of choking or blocked breathing at night (OR = 5.1), sleep talking (OR = 5.0), and a road accident in the past year (OR = 3.9) after controlling for possible effects of sleep deprivation, life stress, and mental and sleep disorders.

CONCLUSION: Arousal parasomnias, especially night terrors and confusional arousals, are often the expression of a mental disorder. Other life or medical conditions, such as shift work or excessive need of sleep for confusional arousals and stressful events for sleepwalking, may also trigger parasomnias. Prevalence rates are based on self-reported data and, consequently, are likely underestimated.




JOURNAL: Neurology 1999 Apr 12;52(6):1194-200
TITLE: Prevalence and pathologic associations of sleep paralysis in the general population.
AUTHOR(S): Ohayon MM, Zulley J, Guilleminault C, Smirne S.


BACKGROUND: Previous epidemiologic data on sleep paralysis (SP) came from small specific samples. The true prevalence and associated factors of SP in the general population remain unknown.

METHOD: A representative sample of the noninstitutionalized general population of Germany and Italy age > or =15 years (n = 8,085) was surveyed by telephone using the Sleep-EVAL questionnaire and the Sleep Questionnaire of Alertness and Wakefulness.

RESULTS: Overall, 6.2% (5.7 to 6.7%) of the sample (n = 494) had experienced at least one SP episode in their lifetime. At the time of the interview, severe SP (at least one episode per week) occurred in 0.8% of the sample, moderate SP (at least one episode per month) in 1.4%, and mild SP (less than one episode per month) in 4.0%. Significant predictive variables of SP were anxiolytic medication, automatic behavior, bipolar disorders, physical disease, hypnopompic hallucinations, nonrestorative sleep, and nocturnal leg cramps.

CONCLUSIONS: SP is less common in the general population than was previously reported. This study indicates that the disorder is often associated with a mental disorder. Users of anxiolytic medication were nearly five times as likely to report SP, even after we controlled for possible effects of mental and sleep disorders.




JOURNAL: Biol Psychiatry 1999 Feb 1;45(3):300-7
TITLE: The prevalence of depressive disorders in the United Kingdom.
AUTHOR(S): Ohayon MM, Priest RG, Guilleminault C, Caulet M.


BACKGROUND: The prevalence of major psychiatric disorders in the general population is difficult to pinpoint owing to widely divergent estimates yielded by studies employing different criteria, methods, and instruments. Depressive disorders, which represent a sizable mental health care expense for the public purse, are no exception to the rule.

METHODS: The prevalence of depressive disorders was assessed in a representative sample (n = 4972) of the U.K. general population in 1994. Interviews were performed over the telephone by lay interviewers using an expert system that tailored the questionnaire to each individual based on prior responses. Diagnoses and symptoms lists were based on the DSM-IV.

RESULTS: Five percent (95% confidence interval = 4.4-5.6%) of the sample was diagnosed by the system with a depressive disorder at the time of the interview, with the rate slightly higher for women (5.9%) than men (4.2%). Unemployed, separated, divorced, and widowed individuals were found to be at higher risk for depression. Depressive subjects were seen almost exclusively by general practitioners (only 3.4% by psychiatrists). Only 12.5% of them consulted their physician seeking mental health treatment, and 15.9% reported being hospitalized in the past 12 months.

CONCLUSIONS: The study indicates that mental health problems in the community are seriously underdetected by general practitioners, and that these professionals are highly reluctant to refer patients with depressive disorders to the appropriate specialist.




JOURNAL: Compr Psychiatry 1998 Jul-Aug;39(4):185-97
TITLE: Comorbidity of mental and insomnia disorders in the general population.
AUTHOR(S): Ohayon MM, Caulet M, Lemoine P.


The co-occurrence of insomnia and mental disorders constitutes the most prevalent diagnosis pattern found in sleep disorder clinics. Yet, there remains a paucity of epidemiological information regarding comorbidity of mental disorders and sleep disorder symptomatology in the general population.

The present study showed results based on a large representative French cohort (n = 5,622; 80.7% of the contacted stratified sample).

A total of 997 (17.7%) individuals with insomnia complaints were identified and divided into six diagnostic categories: (1) Insomnia related to a Depressive Disorder; (2) Insomnia related to an Anxiety Disorder; (3) Depressive Disorder accompanied by insomnia symptomatology; (4) Anxiety Disorder accompanied by insomnia symptomatology; (5) Primary Insomnia; and (6) isolated insomnia symptomatology. Telephone interviews were conducted using the Sleep-Eval System. Subjects with insomnia related to a Mental Disorder have a longer history of insomnia complaints and are usually younger than those with Depressive or Anxiety Disorders accompanied by insomnia symptoms. Subjects with Insomnia related to a Depressive Disorder experienced more repercussions than any other group. A surprisingly high percentage of individuals with depressive symptomatology had sought independent medical treatment specifically for their sleep problems, which raises the unsettling possibility that many cases of depression go undetected by the general medical community.

The distinct predictability of commonly undiagnosed depression leading to chronic depression speaks directly to the imperative that physicians receive additional training in this area of community mental health.




JOURNAL: J Clin Epidemiol 1998 Mar;51(3):273-83
TITLE: Psychotropic medication consumption patterns in the UK general population.
AUTHOR(S): Ohayon MM, Caulet M, Priest RG, Guilleminault C.


The prevalence of psychotropic medication consumption was assessed in the UK by surveying a representative sample of 4972 non-institutionalized individuals 15 years of age or older (participation rate, 79.6%). A questionnaire was administered over the telephone with the help of the Sleep-Eval Expert System. Topics covered included: type and name of medication, indication, dosage, duration of intake, and medical specialty of prescriber. Also collected were data pertaining to sociodemographics, physical illnesses, and DSM-IV mental disorders.

Overall, 3.5% [95% CI: 3-4] of the sample reported current use of psychotropic medication. Consumption was higher among women [4.6% (3.8-5.4)] than men [2.3% (1.7-2.9)], and among the elderly (> or = 65 years of age). The distribution of psychotropics was: hypnotics 1.5%, antidepressants 1.1%, and anxiolytics 0.8%. The median duration of psychotropic intake was 52 weeks. General practitioners were the most common prescribers of psychotropics (over 80% for each class of drug). Nearly half the antidepressant users were diagnosed by the system with a DSM-IV anxiety disorder, and one-fifth the anxiolytic users with a depressive disorder. A marked improvement in sleep quality was reported by half the subjects using a psychotropic for sleep-enhancing purposes. Psychotropic users were more likely than non-users to report episodes of memory loss, vertigo, or anomia.

Psychotropic medication consumption is lower and patterns of psychotropic prescription differ in the UK compared with other European and North American countries. Results suggest that physicians may not be sufficiently trained to deal with the overlap between general practice and psychiatry.




JOURNAL: Arch Intern Med 1997 Dec 8-22;157(22):2645-52
TITLE: How sleep and mental disorders are related to complaints of daytime sleepiness.
AUTHOR(S): Ohayon MM, Caulet M, Philip P, Guilleminault C, Priest RG.


BACKGROUND: Daytime sleepiness is widespread and has negative impacts on the public sector.

OBJECTIVE: To ascertain the incidence and prevalence of daytime sleepiness and associated risk factors in the general population.

METHOD: In 1994, a representative sample of the non-institutionalized British population aged 15 years or older was interviewed via telephone using an expert computer-assisted program designed to facilitate surveys of this type (Sleep-Eval, M. M. Ohayon, Montreal, Quebec). Subjects were classified into 3 groups based on the severity of their daytime sleepiness. We completed 4972 interviews (acceptance rate, 79.6%).

RESULTS: Severe daytime sleepiness was reported in 5.5% (95% confidence interval, 4.9%-6.1%) of the sample, and moderate daytime sleepiness in another 15.2% (95% confidence interval, 14.2%-16.2%). Associated factors with severe daytime sleepiness included female sex, middle age, napping, insomnia symptoms, high daily caffeine consumption, breathing pauses or leg pain in sleep, depressive disorder (based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria), falling asleep while reading or watching television, and motor vehicle crashes or accidents involving use of machinery. Moderate daytime sleepiness was associated with female sex, napping, insomnia symptoms, arthritis or heart disease, and gross motor movements during sleep.

CONCLUSIONS: It is likely that daytime sleepiness deleteriously affects work activities, social and/or marital life, and exhibits a negative socioeconomic impact. In addition, the risk of a motor vehicle crash appears to be higher in this specific population: twice as many subjects operating a motor vehicle or using machine tools reported having a crash or accident, respectively, in the previous year in the groups with severe daytime sleepiness or moderate daytime sleepiness than did the general population with no daytime sleepiness. The high prevalence rates of daytime sleepiness and multiplicity of related factors mandate further scrutiny by public health officials.




JOURNAL: J Clin Psychiatry 1997 Aug;58(8):369-76; quiz 377
TITLE: Violent behavior during sleep.
AUTHOR(S): Ohayon MM, Caulet M, Priest RG.


BACKGROUND: Although the relative incidence of violent behavior during sleep (VBS) is presumed to be low, no epidemiologic data exist to evaluate the prevalence of the phenomenon or to begin to understand its precursors or subtypes. This study examined the frequency of violent or injurious behavior during sleep and associated psychiatric risk factors.

METHOD: A representative United Kingdom sample of 2078 men and 2894 women between the ages of 15 to 100 years (representing 79.6% of those contacted) participated in a telephone interview directed by the Sleep-EVAL expert system specially designed for conducting such diagnostic telephone surveys.

RESULTS: Two percent (N = 106) of respondents reported currently experiencing VBS. The VBS group experienced more night terrors and daytime sleepiness than the non-VBS group. Sleep talking, bruxism, and hypnic jerks were more frequent within the VBS than the other group, as were hypnagogic hallucinations (especially the experience of being attacked), the incidence of smoking, and caffeine and bedtime alcohol intake. The VBS group also reported current features of anxiety and mood disorders significantly more frequently and reported being hospitalized more often during the previous 12 months than the non-VBS group. Subjects with mood or anxiety disorders that co-occurred with other nocturnal symptoms had a higher risk of reporting VBS than all other subjects.

CONCLUSION: We have identified a number of sleep, mental disorder, and other general health factors that characterize those experiencing episodes of VBS. These findings suggest that specific factors, perhaps reflecting an interaction of lifestyle and hereditary contributions, may be responsible for the observed variability in this rare but potentially serious condition.




JOURNAL: Sleep 1997 Dec;20(12):1086-92
TITLE: An international study on sleep disorders in the general population: methodological aspects of the use of the Sleep-EVAL system.
AUTHOR(S): Ohayon MM, Guilleminault C, Paiva T, Priest RG, Rapoport DM, Sagales T, Smirne S, Zulley J.


The comparability among epidemiological surveys of sleep disorders has been encumbered because of the array of methodologies used from study to study. The present international initiative addresses this limitation.

Many such studies using the exact same methodology are being completed in six European countries (France, the United Kingdom, Germany, Italy, Portugal, and Spain), two Canadian cities (metropolitan areas of Montreal and Toronto), New York State, and the city of San Francisco. These surveys have been undertaken with the aim of documenting the prevalence of sleep disorders in the general population according to criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) and the International Classification of Sleep Disorders (ICSD-90). Data are gathered over the telephone by lay interviewers using the Sleep-EVAL expert system.

This paper describes the methodology involved in the realization of these studies. Sample design and selection procedures are discussed.




JOURNAL: Sleep 1997 Sep;20(9):715-23
TITLE: How a general population perceives its sleep and how this relates to the complaint of insomnia.
AUTHOR(S): Ohayon MM, Caulet M, Guilleminault C.


The traditional indicators of insomnia (i.e. difficulty initiating sleep, difficulty maintaining sleep, nonrestorative sleep, early morning awakening) were assessed in a representative sample of 1,722 French-speaking Montrealers (Canada) aged 15 to 100 years. These subjects were interviewed over the telephone (81.3% of contacted sample) by means of the Sleep-Eval software. Subjects were classified as either satisfied or dissatisfied with quality of sleep (SQS or DQS), with or without insomnia indicators (+I or -I). Sociodemographics, sleep-wake schedules, evening activities, medication intake, recent medical consultations, and social life were also investigated.

DQS subjects composed 17.8% of the population (DQS + I: 11.2%; DQS - I: 6.5%), and 21.7% of subjects were classified as either DQS + I or SQS + I. Overall, 3.8% of subjects reported using a sleep-enhancing medication. Nonrestorative sleep did not significantly distinguish SQS and DQS subjects. The complaint of nonrestorative sleep is not a useful indicator of insomnia, despite its inclusion in all medical classifications. DQS - I and SQS + I subjects defy traditional classifications.

A better understanding of sleep complaints and more accurate classifications will help physicians identify patients with insomnia and meet their needs more appropriately.




JOURNAL: Br J Psychiatry 1997 Oct;171:382-8
TITLE: DSM-IV and ICSD-90 insomnia symptoms and sleep dissatisfaction.
AUTHOR(S): Ohayon MM, Caulet M, Priest RG, Guilleminault C.


BACKGROUND: The complex nature of insomnia and its relationship with organic and mental disorders render diagnosis problematic for epidemiologists and physicians.

METHOD: A representative UK sample (non-institutionalised, > 14 years old) was interviewed by telephone (n = 4972; 79.6% participation rate) with the Sleep-EVAL system. Subjects fell into three groups according to presence of insomnia symptom(s) and/or sleep dissatisfaction.

RESULTS: Insomnia symptoms occurred in 36.2% of subjects. Most of these (75.9%), however, reported no sleep dissatisfaction. In comparison, those also with sleep dissatisfaction had higher prevalence of sleep and mental disorders and longer duration of insomnia symptoms, and were more likely to take sleep-promoting medication, dread bedtime, and complain of light sleep, poor night-time sleep and daytime sleepiness.

CONCLUSIONS: Insomnia sufferers differ as to whether they are satisfied or dissatisfied with sleep. Although insomnia symptoms are common in the general population, sleep disturbances among sleep-dissatisfied individuals are more severe. Sleep dissatisfaction seems a better indicator of sleep pathology than insomnia symptoms.




JOURNAL: J Psychiatr Res 1997 May-Jun;31(3):333-46
TITLE: Prevalence of DSM-IV diagnostic criteria of insomnia: distinguishing insomnia related to mental disorders from sleep disorders.
AUTHOR(S): Ohayon MM.


Epidemiological studies of insomnia in the general population have reported high prevalence rates. However, few have applied diagnostic criteria from existing classification systems. Consequently. It is not possible to determine whether subjects suffered from a sleep disorder or whether the insomnia constituted a symptom of a mental disorder. Insomnia and its relationship with other mental disorders was investigated in the general population using DSM-IV criteria. A representative sample of 5622 subjects from the French population were interviewed about their sleep habits over the telephone by lay interviewers. The course and content of interviews were customized by means of the Sleep-Eval knowledge-based system. A total of 18.6% of the sample reported insomnia complaints. The presence of insomnia complaints, lasting for at least one month with daytime repercussions was found for 12.7% of the sample. Subsequently, subjects were classified according to the Sleep Disorder decision-making process proposed by the DSM-IV classification, but without the recourse of polysomnographic recordings. Specific sleep disorder diagnoses were given for 5.6% of the sample, mostly as insomnia related to another mental disorder, primary insomnia was given for 1.3% of the sample. Primary mental disorder diagnoses were supplied for 8.4% of the sample, mostly as generalized anxiety disorder. The results of this investigation emphasize the need to use classifications to determine whether subjects with insomnia complaints suffer from a sleep disorder or whether insomnia constitutes a symptom of some other mental disorder. These distinctions are of utmost importance as they have a bearing on the choice of treatment. Conversely, diagnoses were obtained by lay interviews, which may have caused a lack of recognition and/or discrimination for light or borderline symptomatology.




JOURNAL: Am J Foren Psychiatry 1997;18(4):17-26
TITLE: Violence, sleep and benzodiazepines.
AUTHOR(S): Lemoine P, Lamothe P, Ohayon M.


Numerous papers have reported on the phenomenon of violence committed during sleep after benzodiazepine (BZD) intake.

Such behavior appears paradoxical given that, experimentally, BZDs are classified as sedative and anti-aggressive drugs.

In social groups, however, BZDs can induce aggression in reaction to frustration. REM sleep is physiologically associated with muscle atonia and dreaming. In animals, a lesion of the locus coeruleus can inhibit atonia. In humans, certain degenerative processes can suppress REM muscle atonia as well.

This raises two questions: (1) Are BZDs capable of inducing a feeling of atonia similar to the sensation of being dominated and, consequently, generating aggression?; and (2) Are BZDs capable of dissociating REM criteria to allow a physical expression of violence? Three cases of murder committed during sleep under the effects of BZDs are presented and discussed.




JOURNAL: Sleep 1997 May;20(5):340-8
TITLE: Prevalence of nightmares and their relationship to psychopathology and daytime functioning in insomnia subjects.
AUTHOR(S): Ohayon MM, Morselli PL, Guilleminault C.


A representative sample of 5,622 subjects between 15 and 96 years of age from the noninstitutionalized general population of France were interviewed by telephone concerning their sleeping habits and sleep disorders. The interviews were conducted using the Sleep-Eval knowledge-based system, a nonmonotonic, level 2 expert system with a causal reasoning mode. Questions investigated nightmares, based on the Diagnostic and Statistical Manual, fourth edition (DSM-IV), definition, psychopathological traits, and included 12 other groups of information, including sociodemographics, sleep-wake schedule, daytime functioning, psychiatric and medical history, and drug intake. The data from 1,049 subjects suffering from insomnia were considered for this analysis. Bivariate analyses, logistic regression analysis using the method of indicator contrasts for the investigation of independent variables, and calculation of significant odds ratios were performed.

Nightmares were reported in 18.3% of the surveyed insomniac population and were two times higher in women than in men. The following factors were found to be significantly associated with nightmares 1) sleep with many awakenings, 2) abnormally long sleep onset, 3) daytime memory impairment following poor nocturnal sleep, 4) daytime anxiety following poor nocturnal sleep, and 5) being a woman. There was a strong association between the report of nightmares in women and the presence of either a depressive disorder, anxiety disorder, or both disorders together. When the effects of major psychiatric disorders were controlled for, nightmares were significantly associated with being a woman, feeling depressed after a poor night's sleep, and complaining of a long sleep latency. Nightmares can lead to a negative conditioning toward sleep and to chronic sleep complaints.

Considering the frequency of nightmares in an adult insomniac population and the significant relationship between nightmares and certain subgroups, nightmares should receive more attention in patients, especially women complaining of disrupted sleep, as high rates of psychiatric disorders were found in this specific group.




JOURNAL: BMJ 1997 Mar 22;314(7084):860-3
TITLE: Snoring and breathing pauses during sleep: telephone interview survey of a United Kingdom population sample.
AUTHOR(S): Ohayon MM, Guilleminault C, Priest RG, Caulet M.


OBJECTIVES: To determine the prevalence of snoring, breathing pauses during sleep, and obstructive sleep apnoea syndrome and determine the relation between these events and sociodemographic variables, other health problems, driving accidents, and consumption of healthcare resources.

DESIGN: Telephone interview survey directed by a previously validated computerised system (Sleep-Eval).

SETTING: United Kingdom.

SUBJECTS: 2894 women and 2078 men aged 15-100 years who formed a representative sample of the non-institutionalised population.

MAIN OUTCOME MEASURES: Interview responses.

RESULTS: Forty per cent of the population reported snoring regularly and 3.8% reported breathing pauses during sleep. Regular snoring was significantly associated with male sex, age 25 or more, obesity, daytime sleepiness or naps, night time awakenings, consuming large amounts of caffeine, and smoking. Breathing pauses during sleep were significantly associated with obstructive airways or thyroid disease, male sex, age 35-44 years, consumption of anxiety reducing drugs, complaints of non-restorative sleep, and consultation with a doctor in the past year. The two breathing symptoms were also significantly associated with drowsiness while driving. Based on minimal criteria of the International classification of Sleep Disorders (1990), 1.9% of the sample had obstructive sleep apnoea syndrome. In the 35-64 year age group 1.5% of women (95% confidence interval 0.8% to 2.2%) and 3.5% of men (2.4% to 4.6%) had obstructive sleep apnoea syndrome.

CONCLUSIONS: Disordered breathing during sleep is widely underdiagnosed in the United Kingdom. The condition is linked to increased use of medical resources and a greater risk of daytime sleepiness, which augments the risk of accidents. Doctors should ask patients and bed partners regularly about snoring and breathing pauses during sleep.




JOURNAL: Br J Psychiatry 1996 Oct;169(4):459-67
TITLE: Hypnagogic and hypnopompic hallucinations: pathological phenomena?
AUTHOR(S): Ohayon MM, Priest RG, Caulet M, Guilleminault C.


BACKGROUND: Hypnagogic and hypnopompic hallucinations are common in narcolepsy. However, the prevalence of these phenomena in the general population is uncertain.

METHOD: A representative community sample of 4972 people in the UK, aged 15-100, was interviewed by telephone (79.6% of those contacted). Interviews were performed by lay interviewers using a computerised system that guided the interviewer through the interview process.

RESULTS: Thirty-seven per cent of the sample reported experiencing hypnagogic hallucinations and 12.5% reported hypnopompic hallucinations. Both types of hallucinations were significantly more common among subjects with symptoms of insomnia, excessive daytime sleepiness or mental disorders. According to this study, the prevalence of narcolepsy in the UK is 0.04%.

CONCLUSIONS: Hypnagogic and hypnopompic hallucinations were much more common than expected, with a prevalence that far exceeds that which can be explained by the association with narcolepsy. Hypnopompic hallucinations may be a better indicator of narcolepsy than hypnagogic hallucinations in subjects reporting excessive daytime sleepiness.




JOURNAL: Encephale 1996 Sep-Oct;22(5):337-50
TITLE: [The elderly, sleep habits and use of psychotropic drugs by the French population]
AUTHOR(S): Ohayon MM, Caulet M, Lemoine P.


The aging population in western countries and the increase in longevity make the problem of recognition and treatment of sleep disorders more acute in the elderly population. The risk of evolution of sleep disorders in the elderly leads to a greater weakness of their physical health, a greater dependence on their environment, and finally to more frequent recourse to institutionalization.

We investigated sleep habits, sleep disorders and psychiatric diagnoses, physical illnesses and psychotropic drug consumption in a representative sample of the general population of France. Interviews were performed over the telephone by lay interviews using the Eval Knowledge Based System, a computerized system that guides the interviewer through the interview process, 6966 subjects were contacted, and 5622 interviews (80.8% of the potential sample) were completed. The sample was divided into four age groups: 15 to 44 years old (56.4%); 45 to 64 years old (25.6%); 65 to 74 years old (10.8%) and 75 years old or more (7.2%).

Earlier bedtime, long sleep latency, spending more time in bed with a reduction of nocturnal sleep time, nocturnal awakenings and daytime naps were found more frequently in "young old" (65 to 75 years old) and "old old" subjects (75 years old or more). Daytime naps and spending more time in bed with a reduction of nocturnal sleep time also distinguished "old old" subjects from "young old" subjects. About half of "old old" subjects who complained about their sleep did not get a diagnosis of sleep disorder, nor psychiatric disorder (52.4%). An insomnia diagnosis was given in 14% of cases (mostly primary insomnia-6.7%) and a psychiatric diagnosis in 33.4% of cases (mostly anxiety diagnoses-28.2%). The rate of psychotropic drug consumption was 11.7% (95% Cl: 10.9% to 12.5%) for the entire sample. This consumption dramatically increased with age: 4.8% between 15 to 44 years old; 15.6% between 45 to 64 years old; 24.3% in "young old" subjects and 32.8% in "old old" subjects. Psychotropic drug consumption was distributed as follows: 6.4% of the sample used anxiolytic, 2.7% hypnotic, 1.5% antidepressant and 0.9% hypnotic and anxiolytic together. The chronic use (at least one year) of hypnotic or anxiolytic drugs was frequent in "old old" subjects (92.6% and 80.2%, respectively) and "young old" subjects (74% and 78% respectively).

The assessment of sleep by the physician should be made part of the routine clinical examination of older subjects. Review of the etiology of insomnia complaints is crucial in the choice of treatment. The reflex of psychotropic prescription in case of poor sleep is neither sufficient nor desirable, especially because of the risk of chronic use of the prescription. These data underline the importance of educating physicians about consequences of long-term utilization of these drugs and on the need for sleep hygiene measures as alternative solutions for treating insomnia complaints.




JOURNAL: Can J Psychiatry 1996 Sep;41(7):457-64
TITLE: Psychotropic medication and insomnia complaints in two epidemiological studies.
AUTHOR(S): Ohayon MM, Caulet M.


OBJECTIVE: This study compared prescribed psychotropic medication patterns for reported sleep disorders in French and Quebec samples.

METHOD: The first study was undertaken in France (N = 5622) and the second in the metropolitan area of Montreal (N = 1722). Lay interviewers used a specialized knowledge-based system for the purpose of evaluating sleep disorders by telephone.

RESULTS: Results showed similar prevalence of insomnia complaints in both samples (20.1% and 17.8%, respectively). A higher level of psychotropic consumption was found in France (11.7% [95% confidence interval (CI), 10.9 to 12.5]) compared with Quebec, however, where consumption was less than half the French rate (5.5% [95% CI, 4.4 to 6.6]). Both studies identified females and the elderly as the primary consumers of these drugs. For approximately two-thirds of both samples, sleep-promoting medications were prescribed for a year or longer, revealing a chronicity of the consumption. Approximately 4 out of 5 prescriptions for sleeping medications were ordered by general practitioners in both samples.

CONCLUSION: These findings clearly show a higher prevalence of psychotropic drug use in the French compared with the Quebec population. The patterns of consumption and prescription, however, are quite similar in both studies.




JOURNAL: Sleep 1996 Apr;19(3 Suppl):S7-15
TITLE: Epidemiological study on insomnia in the general population.
AUTHOR(S): Ohayon MM.


This study was conducted with a representative sample of the French population of 5,622 subjects of 15 years old or more. The telephone interviews were performed with EVAL, an expert system specialized for the evaluation of sleep disorders.

From this sample, 20.1% of persons said that they were unsatisfied with their sleep or taking medication for sleeping difficulties or anxiety with sleeping difficulties (UQS). A low family income, being a woman, being over 65 years of age, being retired and being separated, divorced or widowed are significantly associated with the presence of UQS. A sleep onset period over 15 minutes, a short night's sleep and regular nighttime awakenings are also associated with UQS. Medical consultations during the past 6 months and physical illnesses are more frequent among the UQS group. The consumption of sleep-enhancing medication and medication to reduce anxiety is important: in the past, 16% of subjects had taken a sleep-enhancing medication and 16.2% a medication to reduce anxiety. At the time of the survey 9.9% of the population were using sleep-enhancing medication and 6.7% were using medication for anxiety. For most, hypnotic consumption was long-term: 81.6% had been using it for more than 6 months.




JOURNAL: Encephale. 1996 Jan-Feb;22(1):1-6.
TITLE: [Abuse of psychotropic drugs during driving].
AUTHOR(S): Lemoine P, Ohayon M.


The responsibility of psychotropic drugs as a cause of road traffic accidents remains difficult to evaluate with precision. Different studies performed in many countries provide a certain precision in relation to percentage of injured drivers whose blood contained psychotropic substances (8 to 10% according to studies). On the other hand, it is practically impossible to really know either these products were or were not the cause of the accidents because underlying or associated pathologies can equally create problems such as lack of attention and other vigilance deficits. There is also a possibility of suicidal or aggressive tendencies. A certain number of circadian and other chronobiological parameters also complicate the problem since the schedule (hour) as well as the day of the week or even the season can considerably modify vigilance and reaction time.

Available medications able to create such problems are numerous and their mechanisms of action varied. They can influence vision, impulsiveness and vigilance. They can act either by direct mechanisms of sedation or, on the contrary, by raising inhibition through secondary mechanisms: delay in drug elimination or provoked insomnia. For the most part, incriminated medications belong to the different classes of sedative medicines: benzodiazepines, antiepileptics, some antihistaminic agents, some antidepressants, some thymo-regulators and some anti-hypertensives. Also included are desinhibitors or stimulant classes: amphetamines and related drugs, caffeine and codeine. Some of them can be used for their psychodysleptic properties: codeine and anticholinergic drugs.

Finally, drug and medicinal associations can have unforeseen effects: for example, anticholinergics + alcohol + valpromide, etc. If it appears methodologically impossible that research could ever precisely quantify the share of responsibility of psychotropic drugs in causing road traffic accidents, this relation remains highly probable. It is therefore necessary that in the course of university and post-academic training, potential prescribers might regularly be advised of these risks. Lastly, public needs to be constantly informed.




JOURNAL: Prog Neuropsychopharmacol Biol Psychiatry 1995 May;19(3):421-31
TITLE: Insomnia and psychotropic drug consumption.
AUTHOR(S): Ohayon MM, Caulet M.


1. During an epidemiological study conducted by telephone on sleep disorders in the metropolitan area of Montreal (Quebec, Canada), the authors found that 5% of subjects used psychotropic drugs. These drugs were usually prescribed by a general practitioner (72.9%).
2. From this population, the authors drew three groups of subjects: users with sleeping difficulties (USD); non users with sleeping difficulties (NUSD) and, non users without sleeping difficulties (NUWSD).
3. Results showed that the utilization of psychotropics was usually chronic and more frequent among the elderly and women.
4. In multivariate models, when users were compared to NUWSD, the authors found eight variables significantly associated with psychotropic consumption: age (> or = 55), sex (female), presence of physical illness, medical consultation, dissatisfaction with sleep onset period and sleep quantity, sleep onset period greater than 15 minutes, and to never or rarely dream.
5. When users were compared to NUSD, three variables were found to be associated with psychotropic consumption: age, to be formerly married, and to experience regular nighttime awakenings.
6. It appears that the utilization of psychotropic drugs does not increase the quality of sleep when consumers are compared to non treated insomniacs (NUSD) on parameters of sleep satisfaction.




JOURNAL: Medinfo. 1995;8 Pt 2:1071-5.
TITLE: Validation of expert systems: examples and considerations.
AUTHOR(S): Ohayon MM.


The problem of a medical expert system validation is generally complex.

It requires a rigorous methodology of validation and must show proof of its practical competency in order to be used currently. Validation concerns the quality of conclusions provided by the system, the quality of the deductive process leading to these conclusions as well as the validity of its utilization.

In this paper, some reflections, questions, and requirements are exposed that must be addressed to proceed to the validation of a knowledge base system in the field of medicine, especially the psychiatric field.




JOURNAL: Can J Psychiatry. 1993 Apr;38(3):203-11.
TITLE: [Utilization of expert systems in psychiatry]
AUTHOR(S): Ohayon MM.


Are expert systems liable to be used as consultants in psychiatry?

Most expert systems deal with an over-restricted part of psychiatry and cannot be a real help in everyday care. Moreover, most of them are not actually validated (the comparison between the system's and the expert's conclusions in a few cases is not enough). Another problem is that they reflect the uncertainties of nosographic problems.

Validation of such systems needs the careful checking of the logical structure of the underlying nosography, the fitness of the structure's knowledge base and the fitness of the inference engine.

Moreover, the naive use of the system by untrained clinicians is the best means of validation since it provides real life proof of the ability of expert systems to make diagnoses in unselected cases where the need for a common diagnostic reference is clear (for example, epidemiologic, psychopharmacological ornosographic research).

Some of the best known expert systems in the field of psychiatry are reviewed and another expert system, Adinfer, is presented. Developed since 1982, Adinfer is a forward-tracking level O system (in its simplified version for micro-computers). The knowledge base is a translation of the DSM-III-R into production rules. The program has been included in several software packages and used in many clinical studies, both among psychiatrists and physicians. The program has been validated with 1,141 unselected cases, and with 47 physicians: an 83% agreement rate was found between the system's and the physician's diagnoses, taking into account that the clinicians were asked to give their conclusions according to their usual nosography.(ABSTRACT TRUNCATED AT 250 WORDS)




JOURNAL: Can J Psychiatry. 1992 May;37(4):213-20.
TITLE: [Use of the Adinfer diagnostic system in a study of somatic disorders in general practice]
AUTHOR(S): Ohayon MM, Caulet M, Bosc M.


Somatic complaints are very common in general medical practice. They are not identified as psychic disorders and are treated symptomatically.

We explore two kind of problems: 1. methodological problems such as the instruments to use to examine somatic complaints (it is evident that a checklist does not give the best results with suggestible patients); and 2. the relationships between somatic complaints and psychic disorders such as anxiety, depression and somatoform disorders.

Psychiatric nosology is by no means clear and includes many diagnoses from "hysteria" to "hypochondria" or "psychosomatic", "somatization". In this study, we compare the symptoms collected by general practitioners, and their clinical diagnoses to those obtained by an automatic DSM-III diagnostic program. Adinfer was modified so that three DSM decision trees were systematically scanned: depressive, anxiety and somatoform disorders. This allows for an epidemiological study of somatic complaints and their relationship to depression and anxiety. The subjects' score on rating scales for anxiety and depression are compared with the diagnoses made by the expert system. We discuss the significance of somatic symptoms, the DSM classes and the value of expert systems in epidemiological studies.




JOURNAL: Ann Med Psychol (Paris). 1990 Oct;148(8):669-95.
TITLE: [Cognitive processes and neuronal networks].
AUTHOR(S): Ohayon MM.


It is clear that computers are but a poor brain models: the nervous system has many "processors" (neurons) in parallel, whereas von Neuman's machines work sequentially on a single processor.

In complex systems, emergent properties cannot be inferred from the behaviour of single elements. Anthills display collective "meaningful" moves, while each ant seems to obey to local interactions only. Likewise, large parallel networks of processing elements elicit emergent properties. Like brains, some of them are self-organizing systems. In large parallel processing networks, each unit performs an elementary computation: adding inputs from other units. Large nets display surprising spontaneous computational abilities: associative memories, classes, generalizations may be seen as emergent properties of the network. Symbols are dynamical entities, whose handing is driven by local interactions of activation/inhibition of related representations. In such models, representations (memories) are distributed in the whole network, as stable configurations. Indeed, the basic properties of representation in connectionist models seem closer to human mental objects than the classic Artificial Intelligence concepts. Connectionist models have been used in many fields, namely simulations of real neural networks, pattern recognition and artificial vision, speech recognition, language understanding and knowledge representation, problem solving... Connectionist models have been thus used in neurobiology as well as cognition. One basic structure seems indeed able to account for a range of cognitive functions, from perception to problem solving and high level cognitive tasks.

Nevertheless studies about "pathological" networks are yet rare, still an open field... We explore some of these fields.