Hatha yoga for depression: critical review of the evidence for efficacy, plausible mechanisms of action, and directions for future research.

BACKGROUND: The purpose of this article is to review the evidence for the efficacy of hatha yoga for depression and possible mechanisms by which yoga may have an impact on depression, and to outline directions for future research.
METHODS: Literature review and synthesis. RESULTS AND
CONCLUSIONS: A literature search for clinical trials examining yoga for depression uncovered eight trials: 5 including individuals with clinical depression, and 3 for individuals with elevated depression symptoms. Although results from these trials are encouraging, they should be viewed as very preliminary because the trials, as a group, suffered from substantial methodological limitations. We would argue, however, that there are several reasons to consider constructing careful research on yoga for depression. First, current strategies for treating depression are not sufficient for many individuals, and patients have several concerns about existing treatments. Yoga may be an attractive alternative to or a good way to augment current depression treatment strategies. Second, aspects of yoga-including mindfulness promotion and exercise-are thought to be "active ingredients" of other successful treatments for depression. Third, there are plausible biological, psychological, and behavioral mechanisms by which yoga may have an impact on depression. We provide suggestions for the next steps in the study of yoga as a treatment for depression.