Extreme heat a mental health hazard
Intense temperatures increase likelihood of suicide, violence, hospitalizations for disorders
If you find that the blistering, unrelenting heat is making you anxious and irritable, even depressed, it’s not all in your head. Soaring temperatures can damage not just the body but also the mind.
As heat waves become more intense, more frequent and longer, it has become increasingly important to address the impact on mental health, scientists say.
“It’s really only been over the past five years that there’s been a real recognition of the impact,” said Dr. Joshua Wortzel, chair of the American Psychiatric Association’s committee on climate change and mental health, which was set up just two years ago.
“Our understanding of the basic biology of why this association exists is still in its infancy,” he added.
High temperatures are strongly associated with an increase in suicides, researchers have found. Heat has been linked to a rise in violent crime and aggression, emergency room visits and hospitalizations for mental disorders, and deaths — especially among people with schizophrenia, dementia, psychosis and substance use.
For every increase in temperature of 1.8 degrees Fahrenheit scientists have estimated that there is a nearly 5% increase in the risk of death among patients with psychosis, dementia or substance use.
Researchers have reported a 0.7% increase in suicides linked to rising temperatures, and about a 4% to 6% increase in interpersonal violence, including homicides.
Heat not only fuels feelings such as irritability and anger, but also seems to exacerbate mental illnesses, such as anxiety, schizophrenia and depression. Older adults, adolescents and people with preexisting mental illnesses are particularly vulnerable, as are people who do not have housing or are of lower socioeconomic status.
A landmark study last year analyzed data on more than 2 million people with private insurance and found that emergency department visits for mental illnesses were significantly higher during the five or six hottest days of summer, compared with the coolest days of the same season.
The increase was greater in northern parts of the United States, perhaps because these areas are less prepared to cope with heat waves than places like the Southwest, said Amruta Nori-Sarma, an environmental epidemiologist at Boston University School of Public Health, who led the study.
The gap was evident across a range of mental health conditions, including mood and anxiety disorders, stress disorders, schizophrenia, substance use disorders and self-harm. “Extreme heat is an external stressor that seems to be exacerbating people’s mental health symptoms,” Nori-Sarma said.