Sex-specific interplay of combined lifestyle patterns and their association with depressive symptoms among Chinese adolescents: a school-based cross-sectional study.

Background: Unhealthy lifestyle behaviors are known as risk factors for development of depressive symptoms among children and adolescents. Evidence shows sedentary behaviors, sleep duration (SLD), and diet are associated with depressive symptoms. The combination of these lifestyle behaviors may work together to affect mental health. However, the potential role of sex in this association remains unclear. This study aimed to investigate sex-specific associations between combined lifestyle of sugar-sweetened beverage (SSB), screen-based sedentary time (SST) and SLD, and depressive symptoms in Chinese adolescents.

Methods: A school-based study was conducted in Ningbo from 2022 to 2023. A multistage, stratified cluster sampling procedure was used to draw adolescents aged 11–19 years. Depressive symptoms were identified by the Centre for Epidemiological Studies Depression Scale. Multilevel logistic regression was used to examine associations between depressive symptoms and combined lifestyle patterns.

Results: In total, 19,057 adolescents were included for the final data analysis. The prevalence of depressive symptoms was more prevalent in girls (boys vs. girls: 14.54% vs.18.27%; P <0.001). The combination of low SSB consumption, excessive SST and short SLD and the combination of high SSB consumption, excessive SST and short SLD were associated with higher odds of depressive symptoms, while the combination of high SSB consumption, appropriate SST and sufficient SLD was associated with lower risk of depressive symptoms. When stratified by sex, the combination of low SSB consumption, excessive SST and sufficient SLD, and the combination of high SSB consumption, excessive SST and sufficient SLD were associated with depressive symptoms in girls (AOR: 1.48, 95% CI: 0.97–2.25) and boys (AOR: 0.66, 95% CI: 0.49–0.89), respectively.

Conclusion: The association between lifestyle behaviors and depressive symptoms differs by sex. Our findings suggest that sex-specific patterns should be considered when designing future school-based health strategies aimed at promoting healthy lifestyle behaviors and supporting adolescent mental well-being.