Earlier this year (February 2024), researchers led by a team from the University of California San Francisco (UCSF) analysed data from 20,880 individuals collected over seven months, confirming that people with depression tend to have higher body temperatures.
As thorough as the study was however – involving participants from 106 countries – it was not enough to show that a higher body temperature actually causes depression, or indeed that depression is leading to warming of the body.
What it does suggest, is that there’s a connection worthy of further investigation. If something as simple as keeping cool could help tackle the symptoms of depression, then that has the potential to help millions of people around the world.
“To our knowledge, this is the largest study to date to examine the association between body temperature – assessed using both self-report methods and wearable sensors – and depressive symptoms in a geographically broad sample,” said UCSF psychiatrist Ashley Mason when the results were published.
There could be a number of reasons for the link, the researchers think. It might be that depression is 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.
That’s something future studies could look into. For now, we know that depression is a complex and multi-faceted condition, most likely with lots of different triggers, and body temperature could be playing a role.
Previous research has found that hot yoga, hot tubs, and saunas, can lessen the symptoms of depression, albeit in small sample groups. It’s possible that the self-cooling this triggers, through sweating, is having a mental effect too.
“Ironically, heating people up can lead to rebound body temperature lowering that lasts longer than simply cooling people down directly, as through an ice bath,” says Mason.
“What if we can track the body temperature of people with depression to time heat-based treatments well?”
The study data showed that as self-reported depression symptoms became more severe, body temperature averages got higher.
There was also some association between higher depression scores and lower daily temperature fluctuations, but not to a statistically significant level.
With around 5 percent of people around the world thought to be living with depression, efforts to understand and effectively treat it are now more urgent than ever. Each new discovery brings more hope in tackling the problem.
The research has been published in Scientific Reports.
SOURCE: Science Alert
