People with schizophrenia were especially at risk during 2021 heat dome, BCCDC finds

A sign at the BC Centre for Disease Control is seen in this photo from the BCCDC website.

New research from the B.C. Centre for Disease Control suggests people with schizophrenia were particularly susceptible to the deadly heat dome that struck the province in June 2021.

The study, which was published last week in the journal GeoHealth, compared deaths that occurred in B.C. during the heat dome with deaths that occurred on the same dates in previous years. It found roughly three times as many people with schizophrenia died during the heat dome as would have been expected during a "normal" weather pattern. 

In a news release announcing the findings, the BCCDC posited several factors that may help explain why schizophrenia, in particular, was such a risk factor.

Mental illnesses, generally, were among the conditions that left people most susceptible to death during the heat dome, the centre said, adding that schizophrenia's psychotic symptoms – such as hallucinations, delusions, thought disorders and cognitive losses – likely play a role in the increased risk for people with the condition.

"Many people living with schizophrenia also suffer from anosognosia or lack of insight into their own illness," the BCCDC said in its release.

"Schizophrenia may also lead to social isolation and lower socioeconomic status, and both are risk factors for death during extreme hot weather. In addition, some medications used to treat schizophrenia can play a role in overheating."

The researchers said their findings suggest people with schizophrenia, their families and support networks should take extra precautions during extreme heat events.

"Because individuals living with schizophrenia are more susceptible to heat-related illness, it is essential that families and caregivers are aware of the increased risk, identify potential risk factors and take prompt action to help their loved one during a heat wave,” said Faydra Aldridge, CEO of the B.C. Schizophrenia Society, in the BCCDC release.

“Educating ourselves to recognize symptoms of heat-related illness and take emergency cooling measures will help ensure everyone’s safety during heat waves.”

The study looked at 26 chronic conditions, including schizophrenia, and found several others that correlated with increased risk of death, including substance use, chronic kidney disease, ischemic heart disease and chronic obstructive pulmonary disease.

Most of these are "well-recognized risk factors during extreme heat," the BCCDC said.

"This study was conducted to understand who is most at risk, so we can prepare for future heat events, which will be more frequent and more severe in the coming decades because of climate change," said Michael Lee, the study's lead author and an epidemiologist with Environmental Health Services at the BCCDC, in the release.

"Climate change has real impacts on our health, and we can help limit those impacts when we know what they are and how to prepare."