Lifetime prevalence, sociodemographic correlates, and diagnostic overlaps of bipolar spectrum disorder in the general population of South Korea.

BACKGROUND:Patients with subthreshold bipolar disorder (Sub-BP) experience severe clinical courses and functional impairments which are comparable to those with bipolar I and II disorders (BP-I and -II). Nevertheless, lifetime prevalence, socioeconomic correlates and diagnostic overlaps of bipolar spectrum disorder (BPS) have not yet been estimated in the general population of South Korean adults. METHODS:A total of 3013 adults among the 2011 Korean Epidemiologic Catchment Area survey (KECA-2011) completed face-to-face interviews using the Korean versions of the Composite International Diagnostic Interview 2.1 and Mood Disorder Questionnaire (K-CIDI and K-MDQ). RESULTS:The lifetime prevalence of BPS in the South Korean adults was measured to be 4.3% (95% CI 2.6-6.9). Nearly 80% of the subjects with BPS were co-diagnosed with other DSM-IV non-psychotic mental disorders: 35.4% (95% CI 24.2-48.5) for major depression and dysthymic disorder, 35.1% (95% CI 27.7-43.3) for anxiety disorders, and 51.9% (95% CI 40.5-63.1) for alcohol and nicotine use disorders. Younger age (18-34 years) was the only sociodemographic predictor of BPS positivity (P=0.014), and the diagnostic overlap patterns were different between men and women. LIMITATIONS:The prevalence of BPS and other mental disorders could have been influenced by recall bias due to the retrospective nature of this study. CONCLUSIONS:Positivity for BPS was estimated to be much greater than the prevalence of DSM-IV BP in South Korea. Most of the respondents with BPS were diagnosed with other major mental disorders and this might be related with mis- and/or under-diagnosis of clinically relevant Sub-BP.