Impact of physical activities, sedentarism, and sleep on depression and psychological distress-prospective findings of the Canadian longitudinal study on aging

BACKGROUND: The interrelation of physical activity, sedentarism, and sleep concerning the onset and persistence of depression is underexplored. This study examines the joint effect of time spent in these activities on clinically relevant depressive symptoms (CRDS). It also examines the influence of history of depressive disorder and whether results extend to serious psychological distress (SPD). METHODS: Longitudinal data from the Canadian Longitudinal Study on Aging, including 25,665 middle-aged and older (45-85 years) people, were used. Self-reported questionnaires were used for time spent walking, moderate physical activity (MPA), vigorous physical activity (VPA), sitting, and sleep. CRDS and SPD were assessed with the 10-item Center for Epidemiologic Studies Depression scale and the Kessler Psychological Distress scale, respectively. Logistic regression models, adjusted for covariates, estimated the association between activities and mental health outcomes. RESULTS: At baseline, 15 % experienced CRDS, and 11 % SPD. Those with low activity patterns (high sitting levels, low levels of walking, MPA, VPA, and short sleep) were more likely to develop CRDS and to retain it than those with medium-high activity patterns. These patterns mostly also applied to SPD. Among those with history of depression, sedentary behavior and sleep were less strongly related to CRDS, but walking, MPA and VPA were equally strongly related. CONCLUSIONS: Those with low activity patterns (high levels of sitting, little time spent in physical activities) had the worst mental health outcomes, while participants with higher activity level are less likely to continue or develop CRDS and SPD. Short sleep should be targeted for both mental conditions.