This randomized double-blind study (n=338) split participants into two groups: one that received whole-body infrared heat (until their body reached 38.5 C) and one receiving sham mild heat. They completed a baseline questionnaire (Hamilton Depression Rating Scale) in advance. They then received the intervention (heat or sham heat) for 100 minutes. Follow-up assessments were done regularly in the days and weeks following the intervention. ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
The study found significant mood improvement based on the HDRS scores for two weeks following the intervention when compared to the sham group. This response is similar to other new pharmacologic interventions for depression (such as esketamine, ketamine, and scopolamine). Interestingly, the greater the depression the greater the response to heat. ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
Overall, this study presents additional nonpharmacological approaches to treating depression, such as hot yoga, saunas, and taking a hot bath, in medically healthy individuals. Stay tuned for a follow-up study which is planned to identify the mechanism of action behind these findings. ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
Janssen CW, Lowry CA, Mehl MR, et al. Whole-Body Hyperthermia for the Treatment of Major Depressive Disorder: A Randomized Clinical Trial. JAMA Psychiatry. 2016;73(8):789–795. doi:10.1001/jamapsychiatry.2016.1031.