Prevalence of major depressive disorder and minor depressive disorder in an elderly Korean population: results from the Korean Longitudinal Study on Health and Aging (KLoSHA)

Abstract

Objective: We investigated the prevalence, risk factors and impact of major depressive disorder (MDD) and minor depressive disorder (MnDD) in a randomly selected community-dwelling Korean elderly population.

Method: This study was conducted as a part of the Korean Longitudinal Study on Health and Aging (KLoSHA). A study population of 1118 Korean elders was randomly sampled from residents of Seongnam, Korea aged 65 years or older. Standardized face-to-face interviews and neurological and physical examinations were conducted on 714 respondents using the Korean version of Mini International Neuropsychiatric Interview. MDD was diagnosed according to the DSM-IV criteria, and MnDD according to research criteria proposed in Appendix B of the DSM-IV criteria.

Results: Age-, gender- and education-standardized prevalence rates in Korean elders aged 65 years or older were estimated as 5.37% (95% CI=3.72-7.03) for MDD, 5.52% (95% CI=3.84-7.19) for MnDD, and 10.89% (95% CI=8.60-13.17) for overall late-life depression (LLD). A prior MDD episode (OR=3.07, 95% CI=1.38-6.82 in MDD, OR=3.44, 95% CI=1.49-7.94 in MnDD), female gender (OR=3.55, 95% CI=1.53-8.24 in MDD, OR=2.68, 95% CI=1.19-6.04 in MnDD) and history of stroke or TIA (OR=3.45, 95% CI=1.62-7.35 in MDD, OR=2.95, 95% CI=1.34-6.52 in MnDD) were associated with the risks of both MDD and MnDD. Lack of formal education (OR=2.75, 95% CI=1.30-5.85) and low income (OR=2.83, 95% CI=1.02-7.88) were associated with the risk of MDD only. Quality of life (QOL) of the MDD and MnDD patients was worse than that of non-depressed elders (P<0.001, ANOVA).

Conclusion: MnDD was as prevalent as MDD in Korean elders and impacted QOL as MDD did. MnDD patients may increase in the future with accelerated population aging and westernization of lifestyle in Korea.