A new British Columbia study suggests people with schizophrenia may be at higher risk of death during extreme heat events.
The study, conducted by the BC Centre for Disease Control and published in the journal GeoHealth looked at the more than 600 deaths recorded during the 2021 heat dome.
Researchers compared the prevalence of 26 chronic conditions among those who died during the heat dome with people who died over the same period in the previous nine years.
“The risk for people with schizophrenia tripled during the heat dome compared to those typical summer periods,” said Michael Lee, an environmental epidemiologist with the BCCDC.
Lee said the study does not allow researchers to make conclusive statements about why those death occurred, but has allowed them to develop several hypotheses.
“Mental illnesses and schizophrenia are often associated with social isolation and lower socioeconomic status, both of which we know are important risk factors for dying during extreme heat,” Lee said.
“Schizophrenia and other mental health conditions are often treated with antipsychotic and antidepressant medications, some of which are known to affect body temperature regulation.”
Many people with schizophrenia also suffer from a condition called anosognosia, which prevents a person from perceiving their own health status, meaning many may not have realized they were overheating, he added.
The study also found links between depression and deaths during the heat dome. People with depression accounted for 41 per cent of deaths during the control period, while during the heat dome they made up nearly 60 per cent of deaths.
Lee said the study shows the need to improve access to cool indoor air and to increase community support networks for people with mental illness and other vulnerable British Columbians.
He said it’s up to everyone to reach out to those who are vulnerable in their communities to help make sure they understand the risks and have a plan to stay cool during extreme weather.
When extreme heat happens, he said, it’s also crucial that we reach out to those same people to check in on them.
In the wake of the deadly heat dome, the B.C. government made numerous changes around how it communicates extreme heat events.
Those include the use of text alerts and more proactive warnings to reach people at the highest risk.
“We are dealing with health care. We have to deal with broader determinants of health and need to provide support for those with chronic illnesses,” Health Minister Adrian Dix said.
The BCCDC study also found a higher risk of death during extreme heat events for people who use substances and people with chronic conditions such as kidney disease, ischemic heart disease, chronic obstructive pulmonary disease and diabetes, most of which it said were already well-recognized risk factors.
It said it was working with a variety of groups including regional health authorities, BC Mental Health and Substance Use Services and BC Schizophrenia Society to prepare for future heat emergencies.