Temperature extremes can impact mood, including unrelenting heat.
Many people are familiar with seasonal affective disorder (SAD), which is generally attributed to the lack of sunlight and vitamin D during winter months in areas that get snowy and cold. Some individuals notice mood fluctuations, getting particularly sad, depressed and irritable during these months. SAD is actually a recognized mental health condition that is generally treated with a combination of psychotherapy and, often, medication.
However, the effects of heat waves and hot weather on mental health is much less talked about. Nevertheless, these extreme temperature fluctuations can be just as detrimental. High temperatures tend to bring to light underlying mental health conditions as well as exacerbate existing disorders.
“We see across the whole spectrum of mental health that heat extremes are damaging to mental well-being,” said Nick Obradovich, a computational social scientist at the Max Planck Institute for Human Development and co-author of a 2018 study that analyzed the mental health risks of climate change.
Studies have found links between hot temperatures and mental fatigue, aggression and even higher rates of suicide, among other issues.
“This connection is not just limited to surges in temperature,” Dr. Obradovich said, but he added that the findings are also evident with those who live in consistently hot climates, and said, “Evidence suggests that temperature extremes can influence everything from your day-to-day mood all the way up to your probability of experiencing an acute mental health crisis.”
One study published in JAMA Psychiatry in February analyzed the medical records of more than 2.2 million adults who visited emergency rooms (ERs) from 2,775 counties across the United States in the nine-year span between 2010 and 2019. There were “about 8 percent more emergency department visits for mental health concerns on the hottest days of summer than there were on the coolest days,” the authors found. And “emergency visits for issues like self-harm, as well as for substance use, anxiety, mood and schizophrenia disorders, all rose consistently in proportion with the temperature.”
“This trend is fairly uniform for both men and women, for adults of all ages and for people living in all parts of the U.S.,” said Amruta Nori-Sarma, an environmental health scientist at the Boston University School of Public Health.
Other studies have found that high temperatures can be especially impactful on people living with bipolar disorder. Many experience manic episodes during these times. Higher temperatures have also been linked with deaths among people with schizophrenia and other mental health conditions.
Survey data from 1.9 million Americans between 2008 and 2013 found that on days when “temperatures exceeded 70 degrees, respondents were more likely to feel reduced joy and happiness, as well as increased stress, anger and fatigue, than they were on days when temperatures were between 50 and 60 degrees. These associations were especially strong when temperatures were above 90 degrees.”
“When we’re not comfortable, we’re not at our best,” explained C. Munro Cullum, a clinical neuropsychologist at UT Southwestern Medical Center, in Dallas. The heat can be so excruciating that it can be difficult to think about anything else, especially for those living with mental health conditions.