Acute exercise improves cognition in the depressed elderly: the effect of dual-tasks

The goal of this study was to assess the acute effect of physical exercise on the cognitive function of depressed elderly patients in a dual-task experiment.

Physical exercise has a positive effect on the brain and may even act as a treatment for major depressive disorder. However, the effects of acute cardiovascular exercise on cognitive function during and after one session of aerobic training in elderly depressive patients are not known.

Ten elderly subjects diagnosed with major depressive disorder performed neuropsychological tests during and after a moderate physical exercise session (65-75%HR(max)). A Digit Span Test (Forward and Backward) and a Stroop Color-Word Test were used to assess cognitive function. The elderly participants walked on an electric treadmill for 30 minutes and underwent the same cognitive testing before, during, immediately after, and 15 minutes after the exercise session. In the control session, the same cognitive testing was conducted, but without exercise training.

The results of the Digit Span Test did not change between the control and the exercise sessions. The results of the Stroop Color-Word Test improved after physical exercise, indicating a positive effect of exercise on cognition.

These data suggest that the cognitive functions of depressed elderly persons, especially attention and inhibitory control, are not impaired during and after an acute session of physical exercise. In contrast, the effect of dual-tasks showed beneficial results for these subjects, mainly after exercise. The dual-task may be a safe and useful tool for assessing cognitive function.