As the climate crisis worsens, we see farmers whose crops dry up and people losing their homes due to rampant wildfires.
But there is another group for whom the climate crisis is a potentially deadly threat: people with mental health problems such as schizophrenia, bipolar disorder or anxiety.
And this threat has already become a reality for some people. During a record-breaking heat wave in British Columbia in June 2021, 8% of people who died from the extreme heat were diagnosed with schizophrenia, according to a March study. That made the condition a more dangerous risk factor than all the other conditions the authors studied, including kidney disease and coronary artery disease.
"Until climate change is under control, things will unfortunately only get worse," says Dr. Robert Feder, a retired New Hampshire psychiatrist and American Psychiatric Association representative to the Medical Society Consortium on Climate and Health. "As temperatures continue to rise, these effects will be magnified. There will be more storms, more fires, and people will be more concerned about what might happen because there will be a lot more things happening."
Rising temperatures have also been linked to suicide attempts and higher rates of mental health-related emergency room visits, several studies have found. And long-term exposure to air pollution - which can worsen the climate crisis by adding more particles due to drought or wildfires - has been linked to increased anxiety and an increase in suicides.
What's going on in the brains of people with schizophrenia or other conditions is just one factor that makes them more vulnerable to extreme heat, air pollution and stress, experts say - and who need support from loved ones, surrounding communities and policymakers.
Extreme heat and mental health
What makes some psychiatric patients more susceptible to the damage of extreme heat - such as heat stroke or death - starts in a part of the brain called the anterior hypothalamus. Think of it as the body's thermostat.
"That's the part of the brain that works to tell you - when you're too hot or too cold - to shiver, to sweat," which is the body's cooling mechanism, said Dr. Peter Crank, an assistant professor in the department of geography and environmental management at the University of Waterloo in Canada. Crank was the lead author of a March study on the link between temperatures in Phoenix, Arizona, and hospitalizations of people with schizophrenia.
"It tells the rest of your brain to take behavioral action, like drinking water or putting on a jacket when it's too cold or taking off a jacket when it's hot," he added. "These disorders, whether bipolar, schizophrenia or manic-depressive - all three hinder the neurotransmission of information to that part of the brain."
The ability to regulate body temperature may also involve brain chemicals such as serotonin and dopamine, which tend to be lower in the brains of people with these conditions, experts said.
"The hypothalamus is directly dependent on stimulation by serotonin," says Dr. Joshua Wortzel, a psychiatrist at Bradley Hospital at Brown University in Rhode Island and chairman of the American Psychiatric Association's Committee on Climate Change and Mental Health. "Serotonin levels in the brain are affected by the temperatures outside, so you can imagine that if we play with the serotonin levels in the brain with our medications, a person's ability to sweat can change."
Some medications used to treat these conditions may increase the risk by affecting the ability to sweat or increasing the body's core temperature.
Antipsychotic medications - often used to treat schizophrenia, bipolar disorder, paranoia and delusions - have the greatest effect, Feder said. These include aripiprazole, olanzapine, risperidone, quetiapine and lurasidone.
Some stimulant medications for attention deficit hyperactivity disorder or ADHD, such as lisdexamfetamine and amphetamine/dextroamphetamine salts, and anti-anxiety medications can also cause this problem.
Lithium, a mood-stabilizing drug, can cause dehydration, Feder added.
Lifestyle habits that are important for managing mental health symptoms can also take a hit. Hot temperatures can also disrupt sleep, an important factor in managing psychological symptoms, experts said.
Furthermore, "the nature of most mental health problems is that once you are diagnosed, you are at risk for recurrent episodes of that illness," Feder said. "And these episodes are often caused by some form of stress. And climate disasters are certainly stressful."
Homelessness is also high among people with mental health problems, especially among the schizophrenic population.
"And if you're homeless during a heat wave, you're at greater risk of dying because you don't have access to air conditioning," Feder said.
Behaviors caused by these conditions can also contribute to a higher risk of heat-related illness or death. For example, the psychosis that people with schizophrenia may experience may mean that they do not interpret reality correctly, so that they may not even be aware that they are overheating, or they may think that the cause of their overheating is due to a bizarre or irrational reason and not doing something appropriate to get out of the heat or make themselves (safer)," Feder said.
People with mental health problems are also more likely to self-medicate with drugs that interfere with their body's ability to sense and respond to heat.
How to protect yourself and others
If you're taking one of these medications and think that stopping taking them is the solution, not so fast. "That would be much worse than continuing to take the drug," which plays a crucial role in your treatment, Wortzel said.
Talk to your doctor about whether any medication you are taking or starting makes you more vulnerable to extreme heat, as some information brochures for these medications may not list that risk as a possible side effect.
"These are really just warnings," he added, "to really make sure you're staying in a cooler environment and making sure you're hydrated - that if climate change continues to get worse, this will really be a side issue will become. which we will have to worry about more and more."
It's not a reason to stop taking antipsychotics, Wortzel said, but it is a good reason to take care of yourself in the heat.
Addressing the climate crisis, the root of the problem, is of course the most important solution, Wortzel said. What is also needed at the policy level, he added, is expanding access to cooling centers and other resources, and providing more funding for research that would help us better understand the impact of heat on mental health.
There are steps individuals and communities can take to protect vulnerable people when the weather is warm.
"Patients need to be aware that they are vulnerable to stress," Wortzel said. "You need to make sure you have access to air conditioning and a cooling center, to stay hydrated and make sure you monitor how much you're outside, (that) you're not outside during the hottest times of the day. the day, things like that."
Wear sunscreen, hats and light-colored, loose-fitting clothing, Crank said. Taking a cold shower can also keep your core temperature low.
"The other thing people can do is get involved in climate activities," Feder said. "For the fear associated with climate change, the best thing people can do is actually get involved with climate (advocacy) groups and start working to make changes to the climate crisis."
Feder also suggested people write or talk to their lawmakers about the issue.
You should also let your loved ones know about your vulnerabilities so they can provide support.
Correction: An earlier version of this story incorrectly stated which study Dr. Peter Crank was the author.If you are not someone who is at higher risk and are wondering how you can help, practice empathy and awareness by keeping water bottles in your car and handing them out to people who are at higher risk of damage from extreme heat.
"If you see someone in distress, take the time to call 911 so they can receive medical attention," Crank said. This will probably only take a few minutes of your day.
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