Abstract
BACKGROUND: COVID-19 has brought about disruptions in the lives of adolescents, which pose a threat to mental health. While multiple studies have suggested a trend of increased depression during COVID-19, only few have explored the protective factors that could support their mental health during this critical period, highlighting a significant gap in the literature. METHODS: The current study investigated the association between lifestyle modifications and changes in COVID-19-induced depressive mood. By analyzing the data of 54,848 adolescents from a nationally representative sample of the Korea Youth Risk Behavior Web-based Survey (KYRBS), we examined the associations between four lifestyle behavior changes – increased physical activity, increased breakfast consumption, decreased alcohol use, and decreased smoking – and decreased depressive mood during COVID-19 using multinomial logistic regression. RESULTS: Our results indicated that all four lifestyle behavioral changes were associated with the decreased depressive mood in adolescents. Logistic regression model illustrated that the odds ratios (ORs) of decreased depressive mood for each lifestyle behavior change are (1) increased physical activity 2.481 (95% CI 2.311–2.663; p < 0.001); (2) increased breakfast 1.649 (95% CI 1.521–1.783; p < 0.001); (3) decreased drinking 3.169 (95% CI 2.677–3.752; p < 0.001), and (4) decreased smoking 7.113 (95% CI 6.009–8.420; p < 0.001). After accounting for all confounding variables, the odds ratios remained robust and significant. CONCLUSIONS: This study is one of the first large-scale analyses on associations between lifestyle behavior modifications and perceived depressive mood in Korean adolescent population during COVID-19 pandemic. In our study, healthier lifestyle behaviors were significantly associated with a decrease in perceived depressive symptoms, even in individuals at a high risk for mental health issues. Reducing household challenges and enhancing social support can help drive positive lifestyle modifications. During the pandemic, policymakers must secure resources and services, including teletherapy and online tools, that are easily accessible for adolescents. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12888-025-06988-w.