If you struggle with depression or anxiety, have you ever wondered why that sauna or hot bath seems to make you feel better?
Or have you ever marveled at how many people seemed to be almost addicted to doing yoga in unbelievably hot and stuffy rooms (i.e. hot yoga)?
Our research team thinks we have discovered an answer to both these questions. And the answer is simple: Short periods of elevated body temperature (hyperthermia) can be an antidepressant.
We recently did two studies in which we placed individuals with major depression into a high-tech infrared heating device, induced hyperthermia, and then watched to see what it would do to their depressive symptoms.
In the first study of 16 individuals with major depression, a single hyperthermia treatment reduced their depression scores almost by 50% five days later.
The results from this first study were exciting, but the study had a significant weakness: There was no inactive comparative condition (i.e. placebo) that would allow us to know whether the positive effect was specific to the high heat or resulted more from the many non-specific mood-enhancing effects of entering a study.
To address this question, we conducted a second, larger study in which we randomly treated half the participants with active hyperthermia and the other half with a “sham” treatment that mimicked every aspect of the hyperthermia treatment except the high heat. As we describe in a recently published article, the results echoed those found in the first study – a single session of hyperthermia produced a rapid and powerful antidepressant effect. And remarkably, none of this effect was seen in depressed patients who received the sham treatment. Moreover, the benefits of a single hyperthermia treatment persisted for six weeks, something that we weren’t expecting.
Although these results are promising, much more research remains to be done before we can be confident of how best to use hyperthermia to treat depression. Larger studies need to be done to more thoroughly confirm our findings. Also, because we only studied a single treatment we don’t know yet whether giving patients more than one treatment would produce a greater effect or make the antidepressant effect last longer. We also don’t know whether higher or lower amounts of heat would provide stronger results.
I wish I could tell you that if you are struggling with depression and are intrigued by these findings that you could go down to the nearest hyperthermia clinic to give it a try. Alas, although hyperthermia machines are widely used in Europe, they have not been approved for use in the United States by the Food and Drug Administration. So, for now, hyperthermia machines are available only to researchers. For these machines to be approved in the United States, it is likely that larger studies will need to be conducted. Given this, I wouldn’t expect to see them on the U.S. market for at least several years.
In the meantime, saunas and hot yoga may offer some help with depression because they induce at least some degree of hyperthermia. But, to be clear, you should not try to increase the potential antidepressant benefits by lingering longer in the sauna or making your hot yoga even hotter. Heating up the body can be dangerous, so it is important to be mindful of safety. And most importantly, consult with your doctor for specific guidelines that are right for you if you are new to saunas or hot yoga.