Combined patterns of physical activity, screen-based sedentary behaviour and sleep duration and their associations with depressive symptoms in Chinese adolescents

Yi Lin^1*Jin-Ying Huang²Richard Rankin³Stuart McDonald³Danjie Jiang⁴Sixuan Li⁴Wang-Wei Lou⁵Yi Chen⁴Qing qing Gong⁴

• ¹The University of Nottingham Ningbo (China), Ningbo, China
• ²Ningbo University of Finance and Economics, Ningbo, China
• ³University of Nottingham Ningbo China, Ningbo, China
• ⁴Ningbo Municipal Center for Disease Control and Prevention, Ningbo, China
• ⁵Ninghai County Center for Disease Control and Prevention, Ningbo, China

Background Depression is a growing public health burden and one of the leading causes of disability and illness in adolescents. Lifestyle factors are associated with depressive symptoms (DS) in adolescents. This study aimed to estimate the prevalence of DS and investigate the independent and combined associations between DS and moderate-to-vigorous physical activity (MVPA), screen-based sedentary time (ST) and sleep duration (SLD) in Chinese adolescents aged 11-19 years. Methods Repeated cross-sectional data were collected through questionnaires on health status and influencing factors for high school students in Ningbo from a school-based study conducted from September to October in 2022 and 2023. A multistage, stratified cluster sampling procedure was used to draw target adolescents aged 11-19 years. DS was assessed using the Centre for Epidemiological Studies Depression Scale. Multivariate analysis was used to assess the associations between independent lifestyle behaviours (MVPA, ST and SLD) and the combined patterns of those lifestyle behaviours with DS. Results The prevalence of DS among the adolescents was 16.3%. Low MVPA, excessive ST and, short SLD were independently associated with a greater likelihood of DS (all P<0.001). The unhealthiest combined pattern of low MVPA, excessive ST and short SLD was associated with the highest odds of DS (OR:4.2, 95% CI:3.3,5.2, P<0.001). In addition, the other combined patterns of MVPA, sleep duration and ST were significantly associated with an increase in DS compared with the healthy combined patterns of high MVPA, appropriate ST and sufficient SLD. Conclusion Our results indicate that MVPA, ST, and SLD were, independently and in combination associated with an increase in DS. Effective school-based health education programmes aimed at promoting healthy lifestyles are necessary to protect mental health of Chinese adolescents. Future longitudinal studies are needed to confirm causality between the combined lifestyle patterns and DS in Chinese adolescents.