The University of Wisconsin-Madison’s team of scientists has discovered that whole body hyperthermia (WBH), used to raise the core temperature of the body, can be used to treat depression in people not undergoing any other kind of treatment.

The study, published in the influential Journal of American Medical Association Psychiatry on May 12, 2016, saw both welcoming and unenthusiastic responses from the scientific community.  Mr Bernard Carroll, an esteemed psychiatrist in the field of research, wrote a piece for Discover Magazine Blog on how the research was a possible ‘hot mess’.

With participation of nearly 34 people and the final analysis of 29 people, the research results showed that people receiving the therapy witnessed a profound difference in their condition- they became less depressed.

Heat As Antidepressant

The research aimed to discover ‘novel treatments for major depressive disorder’, since the current methods of treatment have a lot of limitations and negative outcomes associated with them. The hypothesis was based on a prior open trial, where placebo control was not used during the proceedings of the research protocols.

The double blind randomized control study was conducted during a six-week period, between February 2013 and May 2015, at a University Medical Center. The participants were selected on the basis of depression as ranked by the Hamilton Depression Rating Scale (HDRS) scores. The only people selected for the study were the ones who were not utilizing any kind of clinical interventions to help them deal with their depression.

Nearly half of the participants were randomized to receive the whole body hyperthermia treatment (WBH), where their core body temperature was raised to 38.5 degrees Celsius or 101.3 Fahrenheit from the normal body temperature of 37 degrees Celsius.

The control group received the ‘sham treatment’ with heat at 37.7 degrees. The mild temperature was used to manipulate patients into thinking that they received the active treatment. The control group also showed similar results, where patients became less depressed,  at a significantly lesser degree than the ‘active treatment’ group.

Mr Bernard Carroll, the critic of the research study, highlights several points which he thinks limit the usefulness of the study.

First, the Cohen’s d effect size is 2.23 for the active group and the HAMD points improved by six points than the sham group.  A score of 0.5 is considered medium and a score of 0.8 is considered large. Mr Carroll thinks that something has gone wrong with the calculations; as such a score of 2.23 is unbelievable in his scientific opinion.

Carroll than further elaborates that the table attached in the article shows that the scientists have confused the standard error (SE) with the standard deviation (SD), thus messing up the calculations.

He also discusses the placebo effect and how it was not clear from the design of the study that it was effective. He fears that there is a possibility of a ‘ceiling effect’ in the active group, making it more likely that their condition will improve. He suggests usage of a more powerful sham effect, like using cooling as a control treatment, which ensures ‘bona fide temperature’ modification.

Edward Shorter PhD, Professor of History of Medicine at the University of Toronto, however, took to Psychology Today to share his optimistic opinion of the benefits this study has to offer. He argues that even though the researchers made some statistical error, the possibility of using heat to treat depression has a historic significance.

The psychologists today use two major therapies, namely psychotherapy and pharmacotherapy. Psychotherapy only became famous as a method of treatment in 1920s after Feud’s psychoanalysis spread like fire at the time of its introduction, though this particular therapy originated in 1880s.  However, Pharmacology, where drugs are used to treat depression, only took off in the 1950s.

A third kind of therapy, namely physical-dietetic therapy, was also used quite successfully to treat psychiatric conditions with the help of heat. Spas were used as treatment centers for this kind of therapy. People who went to these facilities had what we now term ‘depression’.

People there soaked for hours in warm water and also had hot boxes to raise their body temperatures. These boxes at the time used bulbs to generate heat.

Mr Shorter argued that this was also an effective antidepressant therapy and it did not involve any kind of side effects, such as ‘losing your sex life, constipation, or blurred vision’. This history of heat being used effectively as an anti depressant stops him from joining ‘the chorus of dubiety about hyperthermia today’.

The scientists involved in the study explained that this therapy possibly works by activating certain regions of the brain through exposure to raised temperatures. These regions, such as the mid orbitofrontal cortex, the pregenual anterior cingulate cortex, and the ventral striatum, have been previously associated with the increased subjective pleasantness ratings as a result of their activation.