Lifestyle behavior clusters and their associations with depressive symptoms among Chinese adolescents: during and after COVID-19 period

Background: The occurrence of depressive symptoms among adolescents presents a significant public health challenge. However, little is known about the influence of lifestyle changes on depressive symptoms among adolescents after the cancellation of the zero-COVID policy in China. This study aims to examine the associations between clusters of lifestyle behaviors and depressive symptoms among Chinese adolescents during and after the zero-COVID policy period. Methods: A school-based 2-year longitudinal study was conducted from September 2022 to October 2023 in Ningbo, Zhejiang Province, China. Depressive symptoms were assessed using the 20-item Center for Epidemiological Studies Depression Scale. Two-step cluster analysis was used to identify clusters based on adolescents' levels of moderate-to-vigorous physical activities, screen-based sedentary time, sleep duration, and consumption of sugar-sweetened beverages and deep-fried food in each period. A binary generalized linear model (GLM) regression was used to estimate and examine associations between lifestyle clusters and depressive symptoms. Results: A total of 2705 adolescents aged between 10 and 19 years were included in the analysis. The prevalence of depressive symptoms in the zero-COVID policy period was lower than that in the post-zero-COVID policy period (20.00% vs. 25.21%, p < 0.01). Five lifestyle clusters were recognized in each time period. Conclusions: In general, unhealthy lifestyle clusters were associated with a higher likelihood of depressive symptoms, with the association being stronger and more significant in the post-zero-COVID policy period. Effective interventions for adolescents' lifestyle behaviors, such as health education programs, are needed to reduce long-term negative effects on their mental health in the post-pandemic period and potential future pandemics.