Cognitive Function as a Mediator in the Relationship Between Physical Activity and Depression Status in Older Adults.

Previous research has found that increased physical activity may provide a protective effect on depression status; however, these studies do not account for cognitive function. This study's aim was to determine whether cognitive function mediates the association between physical activity depression status in older adults. Data from 501 older adults were used for this analysis. Physical activity had a significant protective effect on depression (OR = 0.761, 95% CI [0.65, 0.89], p = .001). Adjusted analysis yielded an attenuated association (OR = 0.81, 95% CI [0.69, 0.95], p = .01) with a significant interaction for physical activity and cognitive function (OR = 0.991, 95% CI [0.985, 0.997], p = .005). MoCA performance also had a significant mediating effect on the relationship between physical activity and depression status (p = .04). These findings suggest that cognitive function is associated with, and does mediate, the relationship between physical activity and depression status.