Temporal Associations Between Specific Depressive Symptoms and Physical Inactivity in Middle Aged and Older Adults.

Being physically inactive can worsen mental health. Physical inactivity and depression are associated, but the temporal precedence and underlying mechanism are unclear; symptoms affecting future physical activity may not be the same symptoms as those associated with and affected by it. We used large European cohort (Survey of Health, Ageing, and Retirement in Europe, SHARE, N = 124, 526) to study temporal associations between physical inactivity and individual depressive symptoms. Multivariate regression with robust standard errors were used to analyze how physical inactivity is associated with later depression and how depressive symptoms predict later physical inactivity. After adjusting the models for demographics, other health behaviors, BMI, and chronic diseases, physical inactivity was prospectively associated with 10 of the 12 depressive symptoms and 7 of the 12 baseline depressive symptoms were prospectively associated with physical inactivity. These findings were robust for adjusting for antidepressant medication. Age-stratified analyses suggested that the associations between physical inactivity and depressive symptoms were independent of age. Omitting the most influential symptom, lack of enjoyment, from the sum score attenuated the association by 13% in the longitudinal and by 26% in the cross-sectional analyses. These findings suggest that physical inactivity and depression are bidirectionally associated even at symptom-level.