A new UC San Francisco-led study has found that people with depression tend to have higher body temperatures. This could have interesting implications for improving depressive symptoms. In recent times, depression has become a mental health crisis reaching epidemic status. On a global scale, the instances of Major Depressive Disorder (MDD) have been rising in countries across the world. Youth and young adults bear the brunt of depression the most, and face repercussions such as lost opportunities over a lifetime. Studies have also found a significant rise in the intake of antidepressants among people since the COVID-19 pandemic. All these patterns highlight the urgent need to identify and implement new treatment options for depression.
The study stresses that to develop new treatments for depression, it is important to identify mechanisms that contribute to the development of depressive symptoms, and if they can be eliminated through intervention. Thus, it set out to identify physiological differences between those who have MDD and those who don’t. Any physiological characteristic that is common amongst a large number of people with depression, can then be a target for new treatments to reduce depressive symptoms. The characteristic that this study aimed to investigate was body temperature.
This new study, which was published in Scientific Reports, indicates a disparity amongst the body temperatures of individuals with and without a depressive disorder. Researchers analysed data from over twenty thousand international participants belonging to 106 countries. This study, named ‘TemPredict’, was a seven-month study which was initiated in March 2020. For the experiment, the participants were made to wear a sensor device – the Oura Ring – that measures body temperature and collects the data on a smartphone app. They also self-reported their body temperatures (assessed with a handheld thermometer) daily. The study also included monthly mental health assessment surveys which recorded the participants’ depression symptoms.
The results showed that with an increased severity of depressive symptoms, participants’ body temperatures also rose. The study showed that people with depression had an elevated body temperature, especially at night, when the body’s thermoregulatory cooling responses are critical for falling asleep and quality of sleep. The data from the body temperature measurement device also indicated a trend towards higher depression scores in the people whose body temperatures had less fluctuations throughout 24 hours. However, this finding did not reach significance. Notably, the study also suggested that the body temperature dysregulation in people with depressive disorder improved upon their clinical recovery from depression.
However, it is not mentioned in the study, whether depression raises body temperature or a higher temperature causes depression. It is also unknown whether the higher body temperature recorded in people with depression reflects decreased ability to self-cool, or an increased generation of heat from metabolic processes, or a combination of both. Ashley Mason, a PhD scholar, who was the study’s lead author and associate professor of psychiatry at UC San Francisco Neurosciences department, mentioned that the findings of the study shed light on how a new depression treatment might work.
A small body of previously existing studies has already found that using hot tubs or saunas can reduce depression symptoms. This possibly occurs by triggering the body to self-cool, for example, through sweating. Although it sounds ironic, heating people through such methods can lead to rebound body temperature lowering. This lasts longer than directly cooling the body down through methods such as ice baths. As per the lead of the research, it is the largest study to date which examines the association between body temperature and depression. Given the increasing rates of depression, this study shows hope towards new and effective treatment methods for it.