Overdose victims are 15 times more likely to suffer brain injury, new study finds

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Canada’s toxic drug crisis is not only killing thousands of people each year, it also causes lasting harms for those who survive overdoses.

A recent study by B.C. researchers has found people who experienced an overdose were 15 times more likely to have a brain injury than those who didn’t have a history of overdose, after adjusting for age, sex and mental illness. The findings suggest people may need additional support, such as rehabilitation, financial assistance and long-term care, after surviving an overdose, according to author Amanda Slaunwhite, a scientist at the Centre for Health Evaluation and Outcome Sciences and the BC Centre for Disease Control.

Fentanyl and other opioids can slow or stop breathing during an overdose, which can starve the brain of oxygen, similar to a stroke. This can lead to limb weakness, memory loss, vision loss and impairment of motor skills, Dr. Slaunwhite explained.

“Except the thing to keep in mind is we’re not really talking about elderly people here. We’re talking about people in their 20s, 30s, 40s and 50s, and they will then have these issues potentially for many years in the future,” she said.

The study, published in July in the journal Substance Abuse, Treatment, and Policy, examined the health data of a random sample of more than 824,000 B.C. residents. It found 1 per cent of the 5,357 people who had experienced one or more overdoses between 2015 and 2019 had encephalopathy, or brain injury. By comparison, less than 0.04 per cent of those who had never had an overdose had encephalopathy.

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While 1 per cent may seem small, it likely represents only the “tip of the iceberg,” said lead author Chloé Xavier, an epidemiologist at the BC Centre for Disease Control. Not everyone who experiences an overdose accesses health care, she said, explaining the data that she and her colleagues analyzed probably only capture those with the most severe cases of brain injury.

A March, 2021, report from the Public Health Agency of Canada that looked at national statistics, excluding Quebec, found roughly 4 per cent of the 4,433 hospital admissions for opioid-related poisoning between April, 2019, and March, 2020, also involved a brain injury caused by lack of oxygen. The most recent national data, released in June, showed a total of 7,328 apparent opioid deaths occurred in 2022, which is an average of 20 deaths per day. That is double the 2019 average of 10 deaths per day. Public health data also show there were a total of 5,265 opioid-related hospitalizations and 2,086 stimulant-related hospitalizations in 2022. They did not include figures on brain injuries.

While there are supports available for brain injury recovery and for drug rehabilitation, treating both simultaneously can be challenging since many facilities and programs aren’t equipped to handle both, said Rachel Newcombe, manager in strategic initiatives at the non-profit organization Brain Injury Canada, who was not involved in the study.

“It doesn’t mean that there isn’t support out there,” she said, but explained early diagnosis of a brain injury and navigating people to the right resources are needed.

Dr. Slaunwhite also emphasized the importance of giving rescue breaths, or mouth-to-mouth, in addition to naloxone, to people experiencing an overdose if their breathing has reduced or stopped.

Editor’s note: A previously published version of this story said less than 0.4 per cent of those who had never had an overdose had encephalopathy. In reality the figure is much lower. This version has been corrected.