Trends in the Prevalence of Major Depressive Disorder by Sociodemographic Factors in Korea: Results from Nationwide General Population Surveys in 2001, 2006, and 2011

Background: This study investigated trends in the prevalence of major depressive disorder (MDD) by sociodemographic factors in South Korea. Methods: National samples of the general population aged 18 years or older collected from the nationwide Korean Epidemiologic Catchment Area surveys conducted in 2001 (n = 6,206), 2006 (n = 6,466), and 2011 (n = 5,986) were used. For MDD diagnosis, we conducted face-to-face interviews using the Korean version of the Composite International Diagnostic Interview. We performed logistic regression analyses stratified by gender, after adjusting for other sociodemographic variables, to calculate the 2006-to-2001 odds ratio (OR) and 2011 to-2001 OR by subgroups of sociodemographic factors to explore the association of MDD prevalence with sociodemographic factors over time. Results: The prevalence of MDD in the general population of South Korea increased steadily from 2001, to 2006, and to 2011 (1.6%, 2.5%, and 3.1%, respectively). Among the men, the prevalence of MDD continued to increase significantly in 18-29 years of age group (2006: adjusted OR [AOR], 3.32; 2011: AOR, 7.42), at-risk drinking group (2006: AOR, 3.56; 2011: AOR, 4.77), and not living with a partner group (2006: AOR, 3.24; 2011: AOR, 3.25). Meanwhile, among the women, the prevalence of MDD continued to significantly increase in the below-average household income group (2006: AOR, 2.58; 2011: AOR, 2.59), at-risk drinking group (2006: AOR, 2.02; 2011: AOR, 2.47), and unemployed group (2006: AOR, 1.48; 2011: AOR, 2.04). Conclusion: This study may provide significant information for public policymakers to allocate sufficient health resources on MDD to vulnerable groups, particularly, men aged 18-29 years and women living in households with below-average income, and for clinicians to develop appropriate screening and treatment modalities for MDD.