Comparison of treated and untreated major depressive disorder in a nationwide sample of Korean adults.

We examined factors associated with lifetime treatment of major depressive disorder (MDD) in a nationwide sample of Korean adults. Of the 6,510 subjects aged 18-64 years who participated in the Korean Epidemiologic Catchment Area study, 362 (5.6%) with a lifetime diagnosis of MDD were analyzed. Diagnostic assessments were based on the Korean version of the Composite International Diagnostic Interview administered by lay interviewers. Of the 362 respondents with a lifetime diagnosis of MDD, 117 (32.3%) had been treated for psychiatric problems. Treated individuals with MDD were more likely to have chronic episode(s), more symptoms of depression, insomnia, and suicidal ideation, and were less likely to have feelings of guilt. In addition, treated individuals were more likely to have comorbid anxiety disorders, especially obsessive-compulsive disorder, post-traumatic stress disorder, and generalized anxiety disorder. Treatment-seeking by individuals with MDD is affected by socio-cultural factors such as misconception and stigma of mental illness, as well as severity of depression and comorbid conditions.