Prediction of Depression and Anxiety Symptoms in Older Adults from Objectively Measured Physical Activity.

Background: In the context of global population aging, research on physical activity and mental health in older adults is increasingly warranted. While previous studies revealed cross-sectional associations between objectively measured physical activity and depression in older adults, the longitudinal relationship remains unexplored. This longitudinal study aimed to examine the effects of objectively measured physical activity on future depression and anxiety.

Methods: Data were obtained from 477 residents of Nakanojo town who were able to walk independently. Physical activity was measured using an electronic accelerometer, and participants completed the Hospital Anxiety and Depression Scale (HADS) annually. Using these repeated measurements, a longitudinal dataset was constructed by pairing physical activity data with HADS scores measured the following year. Multilevel models were used to predict HADS depression and anxiety scores measured one year after physical activity data collection.

Results: For the depression model, based on 1,963 records from 454 participants, longer durations of moderate to vigorous physical activity (MVPA) were associated with lower depression scores the following year (coefficient = -0.44; 95% confidence interval [CI] = -0.59 to -0.28; p < 0.001). Similarly, in the anxiety model, which included 1,938 records from 452 participants, longer MVPA durations were linked to lower anxiety scores in the subsequent year (coefficient = -0.27; 95% CI = -0.41 to -0.13; p < 0.001).

Conclusions: These findings suggest that higher levels of physical activity may be associated with reduced future symptoms of depression and anxiety in community-dwelling older adults capable of walking.