Background: While controversies on limitation of coverage by the national health insurance and relatively high direct or "out-of-pocket" household payments by the national health insurance in South Korea still remain, potential unfavorable influence of the insufficiency of the universal health coverage on depression has not yet been evaluated.
Methods and findings: Baseline information were obtained from a community cohort (The Korean Genome and Epidemiology Study) of middle-aged subjects without depression at enrollment period (2001-2002). Subjects were followed-up biennially, and new onset depression was assessed using Becks Depression Inventory at 2nd round follow-up (2005-2006). Influence of direct medical expenditure on depression onset was investigated in all subjects and in stratified groups of different income level. Increasing risk of depression onset was observed for increased medical expenditure (OR [95% CI];1.44 [0.97-2.13], 1.90 [1.19-3.05], 1.71 [1.01-2.91] for spending <50000 KRW, 50000-100000 KRW, and ≥100000 KRW, respectively, vs. almost no expenditure per month; P for trend = 0.012), after adjusting for covariates such as monthly income and chronic disease history. Similar associations were observed in subjects less than or at average national income, but results were not significant in subgroup with monthly income above national average.
Conclusions: Even with the universal coverage, high co-payments and uninsured services in the Korean health insurance system yet possibly make the insured pay much for medical service utilization. This might have led to onset of an unfavorable health condition such as depression.