Lower levels of physical activity in childhood predict adult depression

Abstract

Background In cross-sectional and longitudinal community studies, regular exercise has been shown to be protective against the development of depression and has a therapeutic role in depression, while physical inactivity is a demonstrated risk factor for the development of depressive symptoms. Emerging evidence indicates that early life exposures influence adult health outcomes and there is cause to hypothesise a role for physical activity (PA) in childhood as a protective factor in adult depression. This investigation focused on the association between self-reported levels of PA in childhood and self-reported depressive illness in adulthood in a community sample of adult men and women from South-eastern Australia. Methods This study assessed 1404 men (20–96 yr) and 748 women (20–97 yr) participating in an ongoing Australian epidemiological study involving subjects randomly selected from the community (Geelong Osteoporosis Study). A self-report questionnaire based on DSM-IV criteria was utilised to determine lifetime prevalence rates of depression, and another ascertained levels of physical activity (Low PA vs High PA) in childhood, defined as < 15 yr of age. Results In this sample, 141 women (18.9%) and 169 men (12.0%) reported ever having a depressive episode (p < 0.001). Moreover, women were more likely than men to report Low PA in childhood (45.7% vs 23.2%, p < 0.001). Results of logistic regression analyses showed that Low PA in childhood was associated with an increased risk of reporting depression in adulthood (OR = 1.70, 95%CI = 1.32–2.17, p < 0.001). Adjustment for gender attenuated the relationship somewhat (OR = 1.53, 95%CI = 1.19–1.97, p = 0.001), however further adjustment for age and/or country of birth did not affect this relationship. Discussion In this community-based study, lower levels of self-reported PA in childhood increased the risk for self-reported depression in adulthood by more than 50%. These results indicate that lower levels of PA in childhood may be a risk factor for adult depression.