JMIR Publications

ABSTRACT

Background:

Effects of physical activity (PA) across different domains and intensities on depressive symptoms are inconclusive, while it’s critical to incorporate the community-built environment (CBE) into longitudinal reviews of the effects of PA on depressive symptoms.

Objective:

This study aimed to explore the effects of PA at different intensities—low-intensity PA (walking activities) and moderate-to-vigorous intensity PA (activities that require substantial effort and lead to faster breathing or shortness of breath) across leisure time and occupational domains–on depressive symptom trajectories among middle-aged and older adults, and how CBEs affect depressive symptoms and PA trajectories.

Methods:

This longitudinal study included 6865 middle-aged and older adults from the China Health and Retirement Longitudinal Study. A CBE variable system was developed based on a community questionnaire to measure the physical built environment attributes. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale. Latent growth curve modeling was used to analyze three waves of cohort data (2015, 2018, and 2020) to explore the differential effects of PA on depressive symptoms and the role of CBE.

Results:

In waves 2015 and 2018, higher low-intensity leisure-time physical activity (LTPA), was associated with lower depressive symptoms (β = -0.025, P = .011; β = -0.027, P = .005). Moderate-to-vigorous-intensity LTPA showed no significant predictive effects. However, higher occupational physical activity (OPA), particularly higher moderate-to-vigorous-intensity OPA was consistently associated with higher depressive symptoms. Parallel process LGCM revealed that the initial level of total LTPA negatively predicted the initial level of depressive symptoms (β = -0.076, P = .011). OPA showed dual effects, positively predicting the initial level of depressive symptoms (β = 0.108, P < .001) but negatively predicting their upward trajectory (β = -0.136, P = .009). Among CBE variables, better infrastructure conditions (β = -0.082, P < .001) and accessibility of public facilities (β = -0.036, P = .045) negatively predicted the initial level of depressive symptoms. However, greater accessibility of public facilities positively predicted the upward trajectory in depressive symptoms (β = 0.083, P = .040). Better infrastructure conditions (β = 0.100, P = .002) and accessibility of public transport (β = 0.060, P = .013) positively predicted the initial level of total LTPA. Meanwhile, better infrastructure conditions (β = -0.281, P < .001) and accessibility of public facilities (β = -0.073, P < .001) negatively predicted the initial level of total OPA. Better infrastructure conditions positively predicted the declining trajectory of total OPA (β = 0.100, P = .004).

Conclusions:

This study highlights the need to consider the differential effects of PA across domains and intensities on depressive symptoms in public policies and guidelines. Given the environment’s effects on PA and depressive symptoms, targeted community measures should be considered.