The longitudinal effects of depression on physical activity

It has been posited that depression and sedentary lifestyle have bidirectional relationships. Although the role of baseline physical activity as a risk factor for emerging depression has been recently reviewed, there has been no systematic review of the literature to assess the reverse relationship. We reviewed the results of longitudinal studies in the world's literature that have studied the effect of baseline depression on ensuing levels of physical activity.

MEDLINE, PsycINFO, CINHAL Plus, Health Source: Nursing Academic Edition and Cochrane databases were searched from 1959 to 2008 with a focus on depression, sedentary lifestyle and exercise. Published longitudinal studies in English and more than 100 patients were included.

Eleven studies met our inclusion criteria, eight of which reported that baseline depression was significantly associated with subsequent sedentary lifestyle or poor adherence to the physical exercise regimens recommended by physicians after a coronary event. However, the studies used different depression scales and physical activity outcome measures, and varied a great deal in the range of potential confounders they controlled for. In addition, there were only three studies that were specifically designed to assess the role of baseline depression on the subsequent level of physical activity.

Baseline depression may be a significant risk factor for development of sedentary lifestyle or decreased level of physical exercise. Future studies should examine mechanisms by which depression may lead to decline in activity.