Age-varying association between depression symptoms and executive function among older adults: Moderation by physical activity.

Objectives: This study assessed trends in depression symptoms, executive function, and their association across age among older adults. Subgroup comparisons were made between older adults meeting and not meeting physical activity guidelines on variables and associations of interest.

Methods: Participants (n = 2473) were older adults ages 60 to 79 from the 2011-2014 National Health and Nutrition Examination Survey. Depression symptoms, executive function, and physical activity were assessed, and weighted time-varying effect modeling was used for analyses.

Results: Depression symptoms were most severe at age 62 followed by a modest decline before a second peak around age 67. Executive function was highest at age 60 and declined steadily through age 77. Depression symptoms and executive function were negatively associated, but the strength and significance of this association varied with age. Older adults meeting physical activity guidelines had increased executive function and less severe depression symptoms, and meeting physical activity guidelines buffered the association between depression symptoms and executive function at key ages during older adulthood.

Conclusions: Differences by age should be considered when designing and implementing health programs and treatments focusing on mental health and cognition in older adulthood. Encouraging moderate-intensity physical activity may help protect older adults from depression-related cognitive decline.