For this study published in the Journal of Clinical Psychiatry, researchers from Massachusetts General Hospital conducted a controlled randomized trial with adults who were diagnosed with moderate to severe depression who participated in heated yoga sessions for eight weeks. 80 participants were divided into two groups at random: one group received 90-minute sessions of Bikram yoga in a 105°F room, and a second group was placed on a waitlist (these participants completed the yoga intervention at a later date). 33 participants in the yoga group and 32 placed in the waitlist group took part in the study.
Those in the intervention group had to attend at least two weekly classes, and those in this group attended an average of 10.3 classes over eight weeks. According to the researchers, after a two-month period, those in the yoga group displayed a notably greater reduction in depressive symptoms as measured by using the clinician-rated Inventory of Depressive Symptomatology (IDS-CR) scale, compared to the waitlisted controls. Participants tended to rate their heated yoga session positively, and none of the participants reported any serious or adverse side effects in conjunction with the hot yoga intervention.
59.3% of the yoga group had a 50% or greater decrease in symptoms compared to 6.3% of the waitlisted group. 44% of those in the yoga group achieved such a low IDS-CR score that their depression was technically in remission compared to 6.3% of the waitlisted controls. Additionally, even those who only attended half of the yoga sessions experienced reductions in their depressive symptoms, suggesting that one hot yoga session per week could also help.
“Yoga and heat-based interventions could potentially change the course for treatment for patients with depression by providing a non-medication–based approach with additional physical benefits as a bonus,” says lead author Maren Nyer, Ph.D., director of Yoga Studies at the Depression Clinical and Research Program at Massachusetts General Hospital and an assistant professor of Psychiatry at Harvard Medical School. “We are currently developing new studies with the goal of determining the specific contributions of each element—heat and yoga—to the clinical effects we have observed in depression.”
“Future research is needed to compare heated to nonheated yoga for depression to explore whether heat has benefits over and above that of yoga for the treatment of depression, especially given the promising evidence for whole body hyperthermia as a treatment for major depressive disorder,” concludes senior author David Mischoulon, MD, PhD, Director, Depression Clinical and Research Program at Massachusetts General Hospital.
