The projected effect of increasing physical activity on reducing the prevalence of common mental disorders among Canadian men and women: A national population-based community study

Objective. Little quantitative research has been conducted on the effect of physical activity (PA) modification on the prevalence of mental disorders in a nationally representative sample. We aimed to provide quantitative evidence regarding the potential effectiveness of PA in the management of mental disorders. Methods. We used data from the national Canadian Community Health Survey of Mental Health and Well-being (CCHS 12) designed to represent the approximately the 25 million national community population aged 15 years and over in 2002. Results. Around 1 in 10 Canadians reported a 12-month mental disorder. Women reported more mood and anxiety disorders, men more substance dependence. Almost half of Canadians were physically inactive. After adjusting for covariates, physical inactivity was a significant risk factor for common mental disorders, except manic episode. Approximately 780,000 cases nationally are attributable to physical inactivity. A 10% reduction in the rate of physical inactivity would reduce common mental disorders by 167,000 cases, a 25% reduction would result in 389,000 fewer cases. PA was more beneficial for men. Conclusions. Clinicians and public health campaigns targeting individual patients and general populations can improve patients' symptoms and prevent a significant proportion of future mental disorders by increasing the amount of PA. (C) 2012 Elsevier Inc. All rights reserved.