Exercise and Pharmacotherapy in Patients With Major Depression: One-Year Follow-Up of the SMILE Study

Objective: To examine a 1-year follow-up of a 4-month, controlled clinical trial of exercise and antidepressant medication in patients with major depressive disorder (MDD). Methods: In the original study, 202 sedentary adults with MDD were randomized to: a) supervised exercise; b) home-based exercise; c) sertraline; or d) placebo pill. We examined two outcomes measured at 1-year follow-up (i.e., 16 months post randomization): 1) continuous Hamilton Depression Rating Scale score; and 2) MDD status (depressed; partial remission; full remission) in 172 available participants (85% of the original cohort). Regression analyses were performed to examine the effects of treatment group assignment, as well as follow-up antidepressant medication use and self-reported exercise (Godin Leisure-Time Exercise Questionnaire), on the two outcomes. Results: In the original study, patients receiving exercise achieved similar benefits compared with those receiving sertraline. At the time of the 1-year follow-up, rates of MDD remission increased from 46% at post treatment to 66% for participants available for follow-up. Neither initial treatment group assignment nor antidepressant medication use during the follow-up period were significant predictors of MDD remission at 1 year. However, regular exercise during the follow-up period predicted both Hamilton Depression Rating Scale scores and MDD diagnosis at 1 year. This relationship was curvilinear, with the association concentrated between 0 minute and 180 minutes of weekly exercise. Conclusion: The effects of aerobic exercise on MDD remission seem to be similar to sertraline after 4 months of treatment; exercise during the follow-up period seems to extend the short-term benefits of exercise and may augment the benefits of antidepressant use.