“The premise of this is excellent,” says Earric Lee, a physiologist at the Montreal Heart Institute, who was not involved in the study but has led studies on saunas since completing his doctoral research in Finland. “Trying to get away from pharmacology is a good thing.” More than 250 million people worldwide suffer from major depressive disorder and tens of millions of people do not respond to any available treatment.
Such a small study does not prove that sauna therapy can treat depression. “Single-arm studies have significant weaknesses,” Mason admits. The cohort was too small to test multiple scenarios, such as varying degrees of warming, CBT without heat, or a placebo trial. (Tricking people into thinking they’ve had a heat treatment when they haven’t is difficult, but not impossible: The 2016 study on hyperthermia had a placebo group that subjected people to mild heat and convinced 72 percent of the participants that they were receiving the treatment). royal treatment.)
But these results reinforce Mason’s hunch that heat sessions can alleviate the debilitating symptoms of depression, and that this is an avenue that needs to be better explored. Eight weeks of CBT alone should not achieve such high remission rates.
Adam Chekroud, an adjunct assistant professor of psychiatry at Yale University, appreciates the potential benefit of routine hyperthermia, but is skeptical about why Mason’s study produced the reported results. On the one hand, some of the participants completed weekly sauna sessions in Mason’s study, while others completed biweekly sessions; Chekroud believes that the benefit of receiving a “higher dose” of heat would be apparent if the intervention were as potent as that of effective antidepressants. “The placebo effect is powerful in mental health,” he says.
Still, Chekroud sees the value in these explorations. “Much of the history of depression treatments started out as a bit experimental,” he says. Exercise, meditation, and yoga are potentially effective mind-body options. “Exercise is a phenomenally effective treatment,” says Chekroud, pointing to his own 2018 study in The Lancet that analyzed data from 1.2 million people.
Comparing heat therapy to exercise is not entirely unfounded. Beyond simply breaking a sweat and increasing your heart rate, exercise, such as using a sauna, also requires getting out of bed, making a plan, and perhaps interacting with people—actions that themselves can have an impact on mood. . “You will come home and feel proud that you made a change in your life,” Chekroud says. “Psychologically, these are great similarities.”
But the heat itself may also contribute, says Lee, the sauna physiologist. We know that thermoregulation correlates with mood and moves in tandem with circadian rhythms: the body typically cools down at night and warms up early in the morning, but this temperature regulation becomes unstable in severe depression. . This could affect sleep, which is also related to mood.
Doses of extreme heat can have some kind of hacking or resetting effect on thermoregulation, which then changes mood. The sauna can boost the body’s “cooling down” programming, says Lee. “You fake it by making it believe that it needs to lower its temperature much more,” she says. “So it will get there quickly.”
Whatever the mechanism, heat therapy may be more accessible to people than pharmaceuticals, psychotherapy, or vigorous exercise. “We know that exercise works for depression,” Mason says. “It’s much easier to get someone to lie down in a sauna for a while than it is to go for a run for an hour, especially if they have depression.” The same goes for people with disabilities.
Mason’s trial is still several years (and many grant dollars) away from truly determining the effectiveness of antidepressant heat, although the new results have reinforced his optimism. “A mind-body treatment with those kinds of results surely deserves further study,” she says. “I hope grant reviewers and funding agencies agree.” Her long-term goal is to accumulate enough compelling evidence for insurance companies to cover practices like saunas, “so that when a person with depression is considering a menu of treatment options, this is on the menu.”