Lifetime risk and age of onset distributions of psychiatric disorders: analysis of national sample survey in South Korea.

Background: The present study represents the first attempt at examining variation across Korean cohorts with respect to lifetime risk of DSM-IV psychiatric disorders.

Aims: To present data on lifetime prevalence and projected lifetime risk, as well as age of onset (AOO) and demographic correlates of DSM-IV psychiatric disorders as assessed in the nationwide survey of a representative sample of Korean adults.

Method: The survey was based on a multistage area probability sample of non-institutionalized Koreans aged 18-64 years. The Korean version of the Composite International Diagnostic Interview 2.1 (K-CIDI 2.1) was administered by lay interviewers.

Results: Lifetime prevalence of any disorder was 24.6%. Alcohol abuse (9.2%), alcohol dependence (7.0%), major depressive disorder (5.6%), specific phobia (3.8%), and GAD (1.6%) were the most common disorders. The median AOO was earliest for anxiety disorders (age 29), latest for mood disorders (age 47), and intermediate for alcohol use disorders (age 31). Compared to observed lifetime prevalence (24.6%), 35.0% of Koreans will eventually experience one of these disorders. Further, half of the population who present with a psychiatric disorder do so by the age of 32 and younger cohorts are at greater risk for most disorders.

Conclusions: About one-third of the Korean adult population will meet the criteria for a DSM-IV psychiatric disorder at some time during their life. The median age of onset varies from disorder to disorder and younger cohorts appear to be at greater risk for most disorders.