The prevalence of and factors associated with depressive symptoms in the Korean adults: the 2014 and 2016 Korea National Health and Nutrition Examination Survey

Purpose This study was performed to investigate the prevalence of and factors associated with depressive symptoms in the Korean adult population. Methods 10,710 participants in the 2014 and 2016 Korea National Health and Nutrition Examination Survey (KNHANES) were analyzed in this study. Assessment of depressive symptoms was performed using the self-administered nine-item Patient Health Questionnaire (PHQ–9). Results The weighted prevalence of clinically relevant depression (PHQ-9 score ≥ 10) in the Korean adult population was 6.1% [5.5–6.8%]. Female sex, adults aged 19–29 years, elementary school graduation, living alone were significantly associated with clinically relevant depression. Having a household income ≤ 24th percentile was associated with a 2.26 (CI 1.49–3.45, p < 0.001)-fold higher prevalence of clinically relevant depression compared to having a household income ≥ 75th percentile. Regarding occupation, treating managers and professionals as controls, we found that unemployed individuals (OR 2.36, 95% CI 1.52–3.65, p < 0.001) had an increased risk of clinically relevant depression. Alcohol consumption < 30 g/day was reversely associated with clinically relevant depression (OR 0.75, 95% CI 0.62–0.93, p = 0.007), when abstain from alcohol was treated as control. Current smokers (OR 3.42, 95% CI 2.54–4.60, p < 0.001) and ex-smokers (OR 1.73, 95% CI 1.24–2.42, p = 0.001) had a higher risk of clinically relevant depression than never-smokers. Conclusions The estimated prevalence of depressive symptoms in a representative sample of the Korean adult population was 6.1%. This study suggests that younger age, female sex, elementary school graduation, living alone, low household income, current smoking, and being unemployed are associated with depressive symptoms.