Prevalence and Related Factors of Depression Before and During the COVID-19 Pandemic: Findings From the Korea National Health and Nutrition Examination Survey

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has greatly altered the daily lives of people in unprecedented ways, causing a variety of mental health problems. In this study, we aimed to evaluate the prevalence of depression among Korean adults during the COVID-19 pandemic and explore the factors associated with depressive mood using data from the Korea National Health and Nutrition Survey (KNHANES). METHODS: We analyzed participants aged ≥ 19 years from KNHANES 2018 (n = 5,837) and 2020 (n = 5,265) to measure and compare the prevalence of depression before and during the COVID-19 pandemic. Depression was defined as a score ≥ 10 on the Patient Health Questionnaire-9. Furthermore, we performed a multivariate logistic regression analysis to investigate the independent predictors of depressive mood during the COVID-19 pandemic. RESULTS: The prevalence of depression was notably higher during the COVID-19 pandemic than in the pre-pandemic period (5.2% vs. 4.3%, P = 0.043). In a multivariate model, female sex (adjusted odds ratio [aOR], 1.63; 95% confidence interval [CI], 1.10-2.41), age < 50 years (19–29 years: aOR, 7.31; 95% CI, 2.40–22.21; 30–39 years: aOR, 7.38; 95% CI, 2.66–20.47; 40–49 years: aOR, 4.94; 95% CI, 1.84–13.31 compared to ≥ 80 years), unemployment (aOR, 2.00; 95% CI, 1.41–2.85), upper-middle class household income (aOR, 1.83; 95% CI, 1.18–2.85 compared to upper-class income), being a beneficiary of Medicaid (aOR, 2.35; 95% CI, 1.33–4.14), poor self-rated health (aOR, 4.99; 95% CI, 1.51–3.47 compared to good self-rated health), and current smoking (aOR, 2.29; 95% CI, 1.51–3.47) were found to be significant risk factors for depression during the pandemic. CONCLUSION: Depression was significantly more prevalent among Korean adults during the COVID-19 pandemic than in the pre-pandemic era. Therefore, more attention should be paid to individuals vulnerable to depression during pandemics. Implementing psychological support public policies and developing interventions to prevent the adverse outcomes of COVID-19-related depression should be considered.