Extreme Heat Takes a Toll on Mental Health

As temperatures soar across the United States, the news offers daily reminders that extreme heat can be physically dangerous, especially to vulnerable members of the community – infants trapped in cars, the elderly with limited access to cooling, and those working outdoors. But research shows that extreme temperatures can have a significant negative impact on mental as well as physical health, says a psychiatrist at Baylor’s College of Medicine.

You may have noticed that when the temperature rises, people tend to get irritable. Excessive heat can cause emotional and behavioral changes – leading to anger, aggression, discomfort, stress, and fatigue – because heat affects serotonin, the neurotransmitter that regulates mood. Neurotransmitters are brain chemicals that carry messages between brain cells and from the brain to other parts of the body.

Serotonin – known as one of the “happy” hormones – is associated with a positive mood, focus, and a feeling of calm. When heat increases dramatically, serotonin decreases, leading to decreased feelings of joy and happiness and increased feelings of fatigue. According to an article in Psychiatric News, a publication of the American Psychiatric Association, “this is likely because serotonin plays an important role in maintaining the body’s temperature homeostasis.”

Low levels of serotonin are associated with depression. People with preexisting mental health conditions are particularly at risk from these heat-induced changes in serotonin levels.

“All mental illnesses increase with heat because it results in more fatigue, irritability, and anxiety, and it can exacerbate depressive episodes,” explains Dr. Asim Shah, professor and executive vice chair in the Meninger Department of Psychiatry and Behavioral Sciences at Baylor University.

Also at increased risk for mental health are people who use substances like alcohol, because alcohol is a diuretic and dehydrates you. Those using substances need to drink even more water when temperatures rise.

Heat negatively impacts certain medicines used to treat mental health conditions, like lithium prescribed for bipolar disorder. Because lithium is processed through the kidney, if you sweat more, lithium levels are affected.

“If you are out in the heat and using lithium, levels may fluctuate. In that scenario, we have to be very careful and either adjust the dosage of lithium or avoid heat,” said Shah.

Heat exacerbates mental health issues across the board. A study published in JAMA Psychiatry noted that extreme heat led to an 8% rise in emergency rooms visits due to mental health issues.

While it may be impossible to shield yourself from all the adverse effects of a heatwave, Dr. Shah recommends hydrating with electrolytes, moving activities indoors or into the shade whenever possible, and covering your head. Even dousing your head with water can help bring down temperatures. And if you’re struggling with the effects of extreme heat on your physical or mental health, reach out to doctor or mental health professional.

Read the full article here.

Read more on the effects of rising temperatures on mental health at Psychiatry News.

Shalchi, Homa. “Excessive heat and its impact on mental health.” Baylor College of Medicine News, 24 Jul 2023, https://www.bcm.edu/news/excessive-heat-and-its-impact-on-mental-health.