General Information

Official Name Republic of Korea
Capital Seoul
Area 98,488 Sq Km (38,026 Sq Mi)
Population 2002 46,584,500
Location South Korea is located on the southern part of the Korean Peninsula in East Asia.
Geography It is bound by North Korea to the north, the Yellow Sea to the west, the Sea of Japan to the east as well as the Korea and Cheju Straits to the south.
Density (1991) 436 persons per sq km (1,129 persons per sq mi)
Urban-Rural (1990) 74.4% urban
25.6% rural
Sex Distribution (1990) 50.4% male
49.6% female
Life Expectancy at Birth (1990) 67.4 years male
75.4 years female
Age Breakdown (1990) 27% under 15
31% 15 to 29
21% 30 and 44
13% 45 and 59
6% 60 and 74
2% 75 and over
Birth Rate (1990) 15.6 per 1,000
Death Rate (1990) 5.8 per 1,000
Increase Rate (1990) 9.8 per 1,000
Infant Mortality Rate (2003) 15.0 per 1,000 live births



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.


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%.
  • 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. 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%).


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.


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