Randomized controlled trial of bikram yoga and aerobic exercise for depression in women: Efficacy and stress-based mechanisms

Background: The current study presents a randomized controlled 8-week trial of Bikram yoga, aerobic exercise, and waitlist for depression. Bikram yoga was chosen specifically for its standardized nature. Further, we examined changes in three stress-related constructs-perceived stress, rumination, and mindfulness-as mediators of antidepressant effects. Method: Fifty-three women (age 18-65; 74% White) with a unipolar depressive disorder were randomly assigned to one of the three conditions. Response was defined as >50% reduction on the Hamilton Rating Scale for Depression (HAM-D). Remission was defined as no longer meeting criteria for depression and a HAM-D = 7. Self-reported perceived stress, rumination, and mindfulness were assessed weekly. Results: In the intention-to-treat sample (n = 53), response rates were significantly higher in the Bikram yoga (61.1%; chi(2) = 10.48, p = .001) and aerobic exercise (60.0%; chi(2) = 10.44, p = .001) conditions relative to waitlist (6.7%). In the completer sample (n = 42), 73.3% (chi(2) = 11.41, p = .001) of women in yoga and 80.0% (chi(2) = 13.72, p < .001) in exercise achieved response compared to 8.3% in waitlist. Reductions in rumination significantly mediated HAM-D change for both active treatments, and mindful acceptance was a partial mediator in the exercise condition. Limitations: The sample was small in size, consisted of women only, and was ethnically homogenous. Inter-rater reliability was not assessed, aerobic exercise was not standardized, and mediators were assessed by self-report. Conclusions: Bikram yoga showed descriptively similar efficacy to aerobic exercise and both may work, in part, by helping individuals interrupt negative thinking.