Prospective Associations between Physical Activity and Depressive Symptoms in a Large Middle-Aged and Older Adult Cohort Study

Regular physical activity is decisive for bodily and mental health, especially in older individuals. At the same time, mental health, especially depression, affects physical activity levels. When individuals transition from middle to older age, habits related to physical activity, diet and other health-related behaviours can change. Any changes across the follow-up period may be important predictors of depressive symptoms in the middle aged and older adults. This study tests how physical activity and depressive symptoms are related and change over time in a large, representative cohort of mid-aged and elderly individuals. The study’s aim is to estimate how strongly physical activity and depressive symptoms are associated in these later life phases. The study population is a representative sample of middle to older aged adults from the city of Salzburg (40 to 77 years of age at the beginning of the study). Individuals were assessed at baseline, t1 (between 2013 and 2020) and on average 7 years later, at follow-up, t2. Movement habits and depressive symptoms were measured through self-report at baseline and at follow-up. Diagnoses of mental health conditions are assessed through clinician interviews at both timepoints, as a secondary outcome. Covariates of interest include diet, daytime sleepiness, environmental factors and demographic variables.