A couple of summers ago, Stephan Goodwin, a 33-year-old man with schizophrenia living in Phoenix, left his home. He was fleeing the voices he was hearing. Just 36 hours later, after wandering around in 115-degree Fahrenheit heat, despite attempts by family members and emergency responders to locate and help him, he was discovered dead of heat exposure on a vacant lot.
Situations like this are not uncommon. Summer heat waves continue to get hotter and longer as global warming remains largely unimpeded by current efforts. Summer temperatures for 2024 are forecast to be the highest on record. These unprecedented temperatures will bring particular risks to the 20% of Americans who live with some type of mental illness.
Specific Risks for Different Groups
People dealing with depression or substance use disorders make up the vast majority of those with mental illness. Emergency department visits related to depression rise in a dramatic and linear fashion as the ambient temperature rises above 70° F. Suicide rates in the U.S. similarly rise by 0.7% for each 1.8-degree rise in ambient Fahrenheit temperature. Persons with depression are also at increased risk of heat stroke as newer antidepressant medications (SSRIs and SNRIs) increase sweating, which can lead to dehydration, while older antidepressant medications (TCAs) decrease sweating, leading to higher body temperatures.
Persons with substance use disorders have numerous factors leading to increased health risks during heat waves. The euphoria associated with most substances of abuse can cause reduced perception of overheating, leading to dangerously increased body temperature. In fact, 18% of all heat-related deaths involve some type of alcohol poisoning or drug overdose. Alcohol increases dehydration, while stimulants and MDMA (Ecstasy) can directly interfere with hypothalamic temperature control. The poverty and homelessness that, in many cases, accompany severe substance use disorders lead to a lack of air conditioning and lack of access to liquids for these individuals.
Although they represent only a small percentage of those experiencing mental illness, persons with schizophrenia have the highest risk of any group. The risk of death in a heat wave for people with schizophrenia is three times the average for people with any other chronic medical illness, including heart, lung, and kidney disease. Schizophrenia affects only 1% of the total population but was associated with 8% of all heat-related deaths during a particular health wave.
There are numerous reasons for these striking statistics. One factor may be that persons suffering from schizophrenia may have bizarre thoughts related to heat and assistance-seeking. Furthermore, the homelessness and poverty associated with schizophrenia can lead to lack of access to air conditioning and fluids.
Antipsychotic medications impair hypothalamic heat-regulating systems. Anticholinergic medications that are also often taken by persons with schizophrenia reduce sweating and increase body temperature. The illness of schizophrenia itself, aside from any medication effects, also appears to directly impair hypothalamic heat-regulating systems.
Persons with bipolar disorder are often prescribed antipsychotic medication, which reduces their hypothalamic heat-regulating systems. Additionally, these patients often produce more internal heat when in manic states with increased motor activity.
Persons with attention deficit-hyperactivity disorder (ADHD) also tend to have increased activity levels and increased internal heat production. Stimulant medications increase health risks in persons with ADHD through three different mechanisms: impaired hypothalamic heat regulation, reduced sweating, and reduced unpleasant sensations of overheating.
Patients with dementia living in an assisted care facility should, in general, be protected during heat waves as these facilities are usually air-conditioned, and the staff should be trained in guiding the patients in heat-reducing measures. However, persons with dementia living at home may be at increased risk due to several factors. Patients with dementia have decreased awareness of heat and are often confused about what to do when they do feel uncomfortable. Dementia also impairs hypothalamic heat-regulating mechanisms. People with dementia living at home may also have income limitations that restrict their access to air conditioning and adequate fluids.
What Can Health Professionals Do?
Physicians and other mental health providers need to be aware of these increased risks for all of their patients experiencing psychiatric conditions. These patients should be advised to be cautious of high summer temperatures and should be informed of the protective measures they can take to stay cool. These include lowering shades, wearing loose clothing, cooling with cold showers or towels, staying hydrated, and staying in air-conditioned environments. For additional resources, the Climate Psychiatry Alliance has heat wave handouts and posters.
In addition to their patients with mental illness, physicians also need to be aware of the disproportionate burdens of climate change carried by other disadvantaged groups, including the poor, people of color, immigrants, and indigenous peoples. Beyond caring for our patients’ needs, we also need to be doing more than ever to try to reduce global warming directly, by reducing our use of fossil fuels and convincing our legislators to enact appropriate laws and regulations.
Through knowledge, information, and advocacy for resources and change, we can make a big difference for patients facing mental health challenges.
Robert Feder, MD, is a psychiatrist and the American Psychiatric Association representative to the Medical Society Consortium on Climate and Health.
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