Bidirectional relationships between physical exercise and depressive symptoms among Chinese older adults evidence from the China family panel studies

The study aimed to explore the bidirectional causal relationship between physical activity and depressive symptoms in older adults using a multi-wave follow-up design, expanding on established evidence of a bidirectional relationship between physical activity and depression in older adults. Drawing on individual-level tracking data from the China Family Panel Studies (2016, 2018, and 2020), the causal relationship was tested using fixed effects and cross-lagged panel models. Results indicated that physical exercise was a significant negative predictor of depression in older adults across both continuous (beta=-0.056, p < 0.001) and categorical variables (beta=-0.536, p < 0.001). After controlling for unobserved confounders, physical exercise continued to have a significant negative impact on depressive symptoms (beta=-0.024, p < 0.05; beta=- 0.210, p < 0.05). Cross-lagged analyses revealed that physical exercise significantly influenced depressive symptoms only during the T1 -> T2 phase (beta=-0.073, p < 0.001), while depressive symptoms negatively predicted physical activity in later phases (beta=-0.068, p < 0.001; beta=-0.082, p < 0.001). This finding underscores that while physical exercise can positively impact depressive symptoms in older adults, it may not be sufficient during public health crises or social emergencies. A holistic approach, incorporating social support and psychological interventions, is essential for more effective prevention and management of depressive symptoms.