Exercise and pharmacotherapy in patients with major depression: one-year follow-up of the SMILE study

Abstract

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.

Trial registration: clinicaltrials.gov Identifier: NCT00331305.

Figure 1

Flowchart from participant recruitment through the 1-year posttreatment follow-up assessment. MDD = major depressive disorder; PSSS = Perceived Social Support Scale.

Figure 2

Association between self-reported exercise during follow-up and depressive status at 1 year. Panel a displays the association between self-reported exercise and the predicted Hamilton Depression Rating Scale (HAM-D) score at 1 year. Panel b shows the association between self-reported exercise and the predicted probability of being at least partially remitted at 1 year. Estimates are for a typical study participant (age 51 years, white, female, not on antidepressant medication during follow-up, one prior major depressive episode, HAM-D score of 8 at 16 weeks, perceived social support score of 4.5). The expected difference in HAM-D score between a person reporting 180 minutes of exercise and a person reporting 0 minute of exercise was a decrement of 3.1 points (95% confidence interval = −5.1, −1.2). The adjusted odds of being in an improved category of depressive status for a person reporting exercising 180 minutes per week are about three times greater compared with a person reporting 0 minute of exercise.