Longitudinal associations between physical activity and depression scores in Swedish women followed 32 years

Objective: Physical activity is negatively associated with depressive symptoms. However, few studies consider dynamic associations of changes in physical activity and reciprocal relationships. This study aimed to perform comprehensive evaluations of relationships between physical activity and depression scores in women followed from mid-to late life. Method: The Prospective Population Study of Women in Gothenburg, Sweden, provided repeated measures of self-reported physical activity and depressive symptoms between 1974 and 2005 (baseline N = 676, 84.5% response rate). Depressive symptoms were assessed using the Montgomery-Asberg Depression Rating Scale, and physical activity was evaluated by the Saltin-Grimby Physical Activity Level Scale. Latent growth curve analyses were used to evaluate associations of change, and cross-lagged models were used to study the reciprocal relationship between physical activity and depression scores. Results: At baseline, lower levels of physical activity were related to higher depression scores. Individuals with decreasing physical activity over time evidenced higher depression scores at 32-year follow-up. Higher average baseline depression score was related to declining levels of physical activity at subsequent examinations. Conclusion: Reduced physical activity may be a long-term consequence of depression. It is important to address individual changes in physical activity and not merely absolute levels of physical activity in relationship to depression.