Physical activity and depressive symptoms in young adults: a moderated mediation model of neighborhood trust and growth mindset

Introduction While physical activity is widely recognized as an effective intervention for mitigating depressive symptoms among young adults, the psychosocial mechanisms mediating these effects are not yet fully elucidated. Grounded in China’s national fitness campaign and the development of 15-minute community living circles, this study proposes a socio-cognitive integration model to examine community-level mechanisms linking physical activity to reduced depressive symptoms. Methods Drawing on data from the 2022 China Family Panel Studies (CFPS), this study employed generalized structural equation modeling (GSEM) and multiple moderation analyses to examine the mediating role of neighborhood trust and the moderating effect of growth mindset in young adults aged 18–44. Results The mean score for depressive symptoms was 5.67, while the average frequency of physical activity was 1.67. Physical activity directly improved mental health and indirectly reduced depressive symptoms through enhanced neighborhood trust. Notably, growth mindset positively moderated this mediation, with stronger effects observed among individuals endorsing higher growth mindset levels. Conclusion These findings advance psychosocial explanations for physical activity benefits and highlight the value of community environment optimization and mindset-customized interventions.