Why heatwaves kill more mentally ill people, what makes them so vulnerable?

A March study found that 8% of those who died in British Columbia’s record-breaking June 2021 heat wave had a diagnosis of schizophrenia — compared with all other illnesses the authors assessed, such as kidney disease and coronary heart disease. disease. the problem is a more serious risk factor.

“Until climate change is brought under control, things will unfortunately get worse,” said Dr. Robert Feder, a retired psychiatrist from New Hampshire and the American Psychiatric Association’s representative to the Medical Society’s Climate and Health Consortium.

“As the temperature continues to rise, these effects will be magnified. There’s going to be more storms, more fires, and people are going to be more worried about what could happen because there’s a lot more going on.”

According to many researchers, rising temperatures have also been linked to an increase in emergency room visits due to mental health problems and suicide attempts.

In addition, prolonged exposure to air pollution has been linked to higher stress levels and an increase in suicides. The climate crisis has the potential to exacerbate this problem by adding additional particles from fires and droughts.

According to experts, people with schizophrenia or other illnesses are more susceptible to extreme heat, air pollution and stress due to various factors in their brain. Therefore, they require help from loved ones, surrounding communities and politicians.

The anterior hypothalamus, an area of ​​the brain, is the starting point for what predisposes some mental health patients to the negative effects of extreme heat, including heatstroke and even death. Consider it the body’s temperature regulator.

“This is the part of the brain that works to tell you — when you’re too hot or too cold — to start shivering, to start sweating,” which, according to Dr. Peter Crank, assistant professor of geography. and the department of environmental management at the University of Waterloo in Canada, is the body’s cooling system.

A March study looking at associations between Phoenix, Arizona, temperatures and hospital admissions of people with schizophrenia was co-authored by Crank.

“It tells the rest of your brain that you need to take behavioral actions, like drink water or put on a coat when it’s too cold or take off a coat when it’s hot,” he added.

“These disorders, whether they’re bipolar, schizophrenic or manic-depressive — all three impair the neurotransmission of information in that part of the brain.”

Experts hypothesized that brain chemicals such as dopamine and serotonin, which are typically reduced in the brains of those with these diseases, may also play a role in the ability to control body temperature.

“The hypothalamus is directly dependent on serotonin for stimulation,” said Dr. Joshua Wortzel, a psychiatrist at Bradley Hospital at Brown University in Rhode Island and chair of the American Psychiatric Association’s committee on climate change and mental health.

“Serotonin levels in the brain are affected by outside temperatures, so you can imagine that when we play with serotonin levels in the brain with our drugs, that can change a person’s ability to sweat.”

Some drugs used to treat these conditions may increase the risk by raising body temperature or decreasing sweating.

According to Feder, antipsychotic drugs, which are often used to treat schizophrenia, bipolar disorder, paranoia and hallucinations, had the biggest impact. These consist of lurasidone, risperidone, quetiapine, olanzapine and aripiprazole.

This problem can also be caused by certain antidepressants and stimulant treatments for attention deficit hyperactivity disorder, or ADHD, such as lisdexamfetamine and amphetamine/dextroamphetamine salts.

Feder also said the mood-stabilizing drug lithium can lead to dehydration.

Lifestyle choices that are vital to controlling mental health symptoms may also suffer. According to experts, sleep is vital for controlling mental health symptoms and can be disrupted by hot weather.

Additionally, “the nature of most mental health conditions is that once you’re diagnosed with it, you’re at risk for recurrent episodes of that illness,” Feder said. “And these episodes are often triggered by some kind of stress. And climate disasters are definitely a stress.”