Low prevalence of major depressive disorder in Taiwanese adults: possible explanations and implications.

Background: This study examined the prevalence of major depressive disorder (MDD), and the correlations and co-morbid conditions associated with MDD, in the adult Taiwanese population, which a previous estimate in the 1980s had found to be at the lower end of the spectrum worldwide. Possible explanations for the reported low prevalence of MDD were evaluated.

Methods: As part of a survey of common psychiatric disorders in a nationally representative sample of individuals aged ≥ 18 years who were non-institutionalized civilians in Taiwan, a face-to-face interview using the paper version of the World Mental Health Survey of the World Health Organization (WHO) Composite International Diagnostic Interview (WMH-CIDI) was conducted between 2003 and 2005. Functional impairment and help-seeking behaviors were compared between Taiwanese subjects with MDD and their counterparts in the USA.

Results: Among the 10 135 respondents, the lifetime prevalence of MDD was 1.20% [standard error (S.E.)=0.2%]. Individuals who were divorced or widowed, aged ≤ 40 years, and female were at increased risk, whereas rural residents were at lower risk for MDD. The proportion of MDD cases co-morbid with other psychiatric disorders in this study was much lower than in the US study. Only one-third of Taiwanese individuals with MDD sought help despite having twice the number of lost workdays compared with the US sample.

Conclusions: Despite the low prevalence of MDD in Taiwanese adults, the pattern of low help-seeking behavior and profound functional impairment indicates much room for improvement in the early detection of and intervention in major depression in this population.