Independent and relative effects of stress, depressive symptoms, and affect on college students' daily health behaviors.

Stress and depressive symptoms are associated with maladaptive health behavior practices such as unhealthy eating, sedentary behavior, insufficient sleep, and substance use. The relative and interactive effects of stress and depressive symptoms on health behavior practices are less well understood. The present study examined these processes in a daily diary study of 127 college students. Results from hierarchical generalized linear models indicated that depressive symptoms, and chronic and daily stress, but not acute stressful life events, were significantly associated with a composite score of daily maladaptive health behavior engagement (depressive symptoms b = .01, SE= .00, p < .01; chronic stress, b = .03, SE= .01, p < .01; daily stress, b = .01, SE= .01, p = .02); unexpectedly, the effect of stress on health behaviors was not moderated by depressive symptoms. Additionally, results demonstrated that the effect of depressive symptoms on health behaviors was mediated by fluctuations in daily negative affect. These results bear implications for intervention during a crucial period in the development of mental and physical health.