What Body Temperature Can Tell Us About Depression

My husband and I have a dynamic that’s common to many couples. I’m always too cold and he’s always too warm. This becomes apparent at bedtime when he has the window open and a fan on, and I’m wrapped up like a burrito in assorted quilts. When I ask how the weather is and he says it’s comfortable, I know I need to put on at least a sweater before we go out.

What does this have to do with mental health? Well, the statistics on major depressive disorder (MDD) are alarming, especially among teens and young adults. “This is particularly concerning as the disease course is most likely to be malignant, and the costs of depression in terms of lost opportunities across a lifetime are likely to be highest in youth and young adulthood,” note the authors of a recent study. They also suggest that current pharmacological treatments show “significant limitations in efficacy.” So the quest for better treatments is pressing.

That “TemPredict” study found that body temperature correlates with depression. The study involved more than 20,000 people from around the globe. Over approximately seven months, the participants wore a device that recorded their body temperature (an off-the-shelf Oura ring) once per minute via a smartphone app. They also kept daily subjective records of their body temperature and level of depression, so the data collected included that from the wearable sensors as well as self-reports.

“People with depression have higher body temperatures, suggesting there could be a mental health benefit to lowering the temperatures of those with the disorder, a new UC San Francisco-led study found,” according to UCSF. The study was reported in the journal Scientific Reports.

The results? People with depression have higher body temperatures than those without, particularly at night. This had been suggested by smaller studies, but the new one is much more comprehensive. Of course, the study couldn’t really say whether depression causes higher body temperatures or whether higher body temperatures cause depression. The authors caution that “although no single biological or behavioral abnormality will characterize all individuals with MDD, the identification of an abnormality associated with MDD may open the door” to new treatments.

The study’s authors also indicated that “it is uncertain whether the elevated body temperature observed in depression reflects increased metabolic heat production, decreased ability to induce thermoregulatory cooling, or a combination of both.” In other words, “depression [may be] tied to metabolic processes that generate extra heat perhaps, or tied to cooling biological functions that aren’t operating properly. Or there might be a common shared cause, such as mental stress or inflammation that impacts both body temperature and depressive symptoms separately.” So there are still aspects that need to be studied further.

What’s also interesting is that the study suggested that warming people up has a more cooling effect than directly cooling them with ice water, perhaps because of sweat’s cooling effect. At any rate, people who soak in hot tubs have a rebound factor that actually cools them off. (Personally, I wouldn’t mind if someone prescribed me a hot tub.)

The hope is that the results of the study will lead to new treatments for depression.