Yoga as a means of treating depression has shown an association with lower depressive symptoms only for individuals with a high level of expectancy for treatment, according to a study recently published in the Journal of Affective Disorders.
The original trial investigated in this secondary analysis which included 122 participants with depression, all of whom attended a maximum of 20 classes over a 10-week period. Other individuals engaged in a health education program and served as a control group. Treatment engagement was not significantly related to treatment expectancy, credibility, or concordance.
Treatment expectancy did play a moderating role between depression and treatment group, with higher levels of expectancy correlating with lower depressive symptoms over time for those engaged in yoga but not control. Credibility followed a similar trend, though concordance did not show any significant association with outcome of treatment.
Assessments of individuals in the randomized controlled trial were performed at baseline and after 3 and 6 months. Treatment preference was reported before random assignment, and treatment expectancy and credibility were reported following the participants’ first class. Concordance was a measure of whether the participants had been assigned to their preferred method of treatment.
Limitations include the fact that this study was a post-hoc analysis, and the study researchers note that it should be viewed as a hypothesis-generating investigation.
The study researchers conclude that “expectancy improves the likelihood of success only for [an] intervention thought to actively target depression (yoga) and not a control intervention.”
Uebelacker LA, Weinstock LM, Battle CL, Abrantes AM, Miller IW. Treatment credibility, expectancy, and preference: Prediction of treatment engagement and outcome in a randomized clinical trial of hatha yoga vs. health education as adjunct treatments for depression. J Affect Disord. 2018; 238:111-117.