Data from over 20,000 people reveals an interesting link between depression and body temperature. Specifically, people with depression recorded slightly higher body temperatures. Although there are still many questions to answer, this study raises the possibility of introducing heat-based treatments into mental health care in the future.
The study lasted seven months starting in early 2020 and involved volunteers from 106 countries. Participants tracked body temperature data using the Oura wearable smart ring, a commercially available fitness tracker. The main goal of the study, called TemPredict, was to assess whether body temperature tracking could be a useful tool for early detection of COVID-19, with results to be reported in 2022.
In addition to recording their body temperature once a day, participants completed a monthly questionnaire that included a diagnostic questionnaire regarding symptoms of depression.
Examination of the data revealed that people with higher levels of depressive symptom severity tended to have higher body temperature readings. People with more stable body temperatures over a 24-hour period also tended to have more severe depression, but this finding was not statistically significant.
Mean self-reported (A) and wearable-rated body temperature (B) by depression symptom score (red indicates the most severe depressive symptoms).
This is not the first time that a link, albeit tentative, between depression and body temperature has been made, but disentangling the causes of some of the observed differences has proven more difficult. This large-scale study will no doubt help add more pieces to the puzzle, but we can’t say with certainty whether depression causes elevated body temperature or whether higher-than-average body temperature is a risk factor for depression. I can’t do that yet.
We also don’t know whether the higher body temperatures recorded in people with depression are because their bodies are producing more heat than normal, or because their ability to regulate body temperature is impaired.
This is something that Ashley Mason, lead author of the study and associate professor of psychiatry at the Weill Neuroscience Institute at the University of California, San Francisco, is interested in further research. A small body of evidence suggests that heat-based treatments for depression, such as saunas and hot yoga, have potential benefits. Artificially increasing someone’s body temperature can trigger self-cooling mechanisms in the body, such as sweating.
“Ironically, actually warming a person can cause a reactionary drop in body temperature that lasts longer than directly cooling the person, such as with an ice bath,” Mason said in a statement. “What if we could track the body temperature of depressed patients and time their heat therapy appropriately?”
Depression is a common problem, with an estimated 1 in 5 U.S. adults diagnosed with depression. As a result, antidepressant use in some regions is at an all-time high, but these do not work for everyone and can come with troubling side effects.
The scientific quest to develop new and better treatments for depression continues and includes research into alternative treatments such as psychedelics, drugs such as ketamine, and sensory deprivation. Perhaps heat treatment could someday be part of that package, the authors suggest.
“To our knowledge, this is the largest study to date investigating the association between body temperature, assessed using both self-report methods and wearable sensors, and depressive symptoms in a geographically wide sample. ,” Mason said.
“Given the rising incidence of depression in the United States, we are excited about the possibility of new treatments.”
The study is published in Scientific Reports.