(PS14-90) Effects of Whole Body Hyperthermia Treatments on Symptoms of Anxiety and Perceived Stress

Background: Despite the increase in the availability of therapies to treat major depressive disorder (MDD), a large percentage of individuals do not respond at all or do not respond to the full extent to available treatments. Whole body hyperthermia (WBH) stands as a promising new treatment for MDD that uses a medical-grade sauna device to increase core body temperature to that of a mild fever (101.3F). A recent randomized controlled trial (RCT) found that a single session of whole-body hyperthermia (WBH) significantly reduced symptoms of MDD for 6 weeks compared to a believable sham. However, this study did not assess commonly associated constructs of MDD such as stress and anxiety. We are currently conducting a follow-up RCT of WBH for MDD and aim to understand the secondary outcomes of perceived stress and anxiety.  

Methods: The present investigation is an interim analysis of a larger RCT focused on WBH vs. a sham for MDD. The anxiety subscale of the PROMIS-29 was used to measure anxiety, and the Perceived Stress Scale (PSS) was used to measure stress. Participants completed these self-report measures at baseline, before the WBH intervention visit, and at the primary four-week endpoint.

The total screened sample consisted of 29 adult individuals (58.6% female, 57.1% White, M_age = 32.8 ± 11.1). Paired Samples T-Tests tested whether anxiety and stress improved overall among both conditions between the baseline and primary four-week endpoint, and Independent T-Tests tested the difference in anxiety and stress between the WBH condition and the Sham condition between the baseline and four-week endpoint.

Results: Of the 29 participants screened, 21 participants were analyzable (10 WBH, 11 Sham). Results indicated that a single session of WBH or Sham significantly improved anxiety between the baseline (M = 11.33, SD = 3.75) and primary endpoint (M = 8.05, SD = 4.08, t (21) = 4.41, p < .01) . Additionally, a session of WBH or Sham significantly improved stress between the baseline (M = 24.90, SD = 5.65) and primary endpoint (M = 18.48, SD = 7.52, t (21) = 5.41, p < .01)  However, results indicated no significant difference in anxiety between baseline and primary endpoint between the WBH (M = 2.50, SD = 3.75) and Sham (M = 4.00, SD = 3.10, t (21) = 1.00, p = .33). Additionally, results indicated no significant difference in stress between baseline and primary endpoint between the WBH (M = 6.40, SD = 6.79) and Sham (M = 6.45, SD = 4.23, t (21) = .02, p = .98). 
Conclusion: These results indicate that a single session of either WBH or Sham significantly decreases anxiety and stress. Additionally, the null findings indicate that there was no significant difference in the ability to reduce anxiety or stress between WBH vs. Sham. These results may be due a strong placebo effect found in the Sham condition. Alternatively, the Sham condition may provide a mildly active treatment effect, leading to a reduction in anxiety and stress. When the entire sample completes the study, we will continue to investigate whether WBH may improve mental health symptoms, as it is a safe and increasingly accessible treatment alternative.