Trends in depressive episodes in pre-, intra-, and post-COVID-19 pandemic periods among South Korean adults

The COVID-19 pandemic has brought about significant social changes that could potentially affect mental health. This study aimed to examine the association between specific periods of the pandemic and depressive symptoms in South Korean adults. We used cross-sectional data from 1,376,438 participants involved in the 2019–2024 Korean Community Health Survey. The pandemic period was categorized into pre-COVID-19 (2019), intra-COVID-19 (2020–2022), and post-COVID-19 (2023–2024) periods. Depressive episodes were assessed using the Patient Health Questionnaire-9. Multivariate logistic regression was used to estimate the odds of depressive episodes across the time periods. Compared to the pre-pandemic period, individuals assessed during the intra-COVID-19 period had higher odds of depressive episodes (odds ratio [OR] = 1.23; 95% confidence interval [CI]: 1.19–1.27). The odds further increased in the post-COVID-19 period (OR = 1.41; 95% CI: 1.36–1.45). The association was greatest among adults aged 20–39 years old. Depressive symptoms were more common during and after the pandemic, particularly among younger adults. These findings emphasize the need for long-term mental health support in the post-COVID-19 pandemic era.