Drug overdoses in B.C. are causing 'irreversible' brain damage, experts say

Research out of B.C. is showing that drug overdoses can cause “irreversible brain injury.”

In a letter to the editor published in the journal Addiction, researchers are calling for clinicians and systems to change how they handle opioid overdose risk — and to focus on preventing overdoses in the first place.

The same researchers also recently published a study in Addiction based on data from B.C., which showed that within one year of a first overdose, adults have a six per cent risk of being diagnosed with a brain injury. People under the age of 19 have a 10 per cent risk.

This is because when someone overdoses, they stop breathing.

“And the minute a person stops breathing, brain cells start to die. And so, depending on how long that anoxia, which is the lack of oxygen in the brain, happens, that is the extent of the acquired injury that the person will have,” said Dr. Daniel Vigo, the chief scientific advisor for psychiatry, toxic drugs, and concurrent disorders for B.C., in an interview with Daily Hive.

Dr. Vigo, who is also a co-author of the study in Addiction, said his goal as an advisor to the Province is to improve the services for people with the most severe forms of mental disorders, substance use disorders, and acquired brain injury.

In this role, has access to provincial administrative data that reflect the health care encounters of people in the province.

“I basically counted people with those illnesses — how many are they every year? How is that evolving?” he said in an interview with Daily Hive.

Through this, he said they confirmed something that “anyone who lives in B.C. realizes” — the people who suffer the most from exposure to toxic drugs are those who already have severe mental illness, like schizophrenia or bipolar disorder.

In the past decade, over half the overdose episodes and 40 per cent of the overdose deaths have affected people with severe mental illness, “for whom most addiction services are woefully inadequate,” Dr. Vigo said.

Between 2015 and 2024, there were 256,000 non-lethal drug overdoses in B.C.

He added that while the most severe brain injury is diagnosed and is reflected in B.C.’s data, there is also a “much larger group of people who have acquired brain injury, but that is not registered in their medical records.”

Why have drug overdoses increased so much?

Drugs have become increasingly toxic since 2013, when people started manufacturing synthetic opioids that “are significantly more potent than old opioids,” Dr. Vigo said. These drugs, which include fentanyl, can be manufactured anywhere and are very difficult to stop.

“So you can imagine that the person who is cutting those powders in a back shed somewhere, with no knowledge about how to do it safely, is exposing people to an opiate that immediately produces respiratory depression,” said Dr. Vigo.

Dr. Nathaniel Day, a co-author of the letter and chief scientific officer at the Canadian
Centre for Recovery Excellence (CoRE), said in the press release that overdoses can create long-term problems in memory, decision-making, and impulse control.

“Contact sports, including hockey and football, have recognized that even minor brain injuries can accumulate over time and become a serious injury. Each overdose carries the risk that real brain damage is occurring, changing a person’s ability to function normally. This makes preventing the next overdose an urgent priority.”

What can be done?

Dr. Vigo said in the release that there are “hundreds of thousands of people in B.C. with brain injuries, frequently caused by overdose,” with thousands of them also suffering from severe mental illness and addiction.

He added that health systems need to have the “unwavering goal of preventing addiction whenever possible, and treating it whenever present.”

He told Daily Hive that B.C. has a siloed delivery of addiction and mental health services, meaning they aren’t integrated, which is why he thinks the problem is so severe for people with mental illness.

For example, he said that people with addiction (but not mental illness) have “excellent services” available. But most people with mental illness do not get access to addiction services, like a detox bed, withdrawal management bed, or recovery management bed.

Further, for the past 10 years, the focus in B.C. has been on harm reduction measures, which he acknowledged has been for “good reasons.”

“Some of them are extraordinarily effective, such as the distribution of naloxone kits,” he said.

However, while naloxone can reverse an overdose by displacing the opioid from the neuron, it doesn’t reverse the damage that has already been done.

Dr. Vigo said that they could instead give people who are overdosing buprenorphine, which he says has the ability to put “a ceiling on the degree of respiratory depression that that person can have.”

Further, Dr. Vigo said that early, evidence-based interventions at schools are important to steer children away from harmful drugs and addiction in the first place.

“And again, not every drug. We’re talking about these synthetic drugs, which basically kill neurons. There’s no two ways about it, right? There’s no way of using these drugs outside of a hospital setting without killing neurons.”

B.C. declared the toxic drug crisis a public health emergency in April 2016. From January 2016 to January 2026, the province saw over 18,900 unregulated drug deaths. Since then, B.C. has tried various drug policy pilots to prevent deaths, with some becoming quite controversial.

For example, at the beginning of the year, the Province backed away from its three-year drug decriminalization pilot, stating that it didn’t deliver the results they had hoped for. The pilot had allowed anyone in B.C. aged 18 or older to possess up to 2.5 grams of MDMA, methamphetamine, cocaine, or opioids for personal use. For three years, individuals didn’t face arrest for possession, nor could police seize the substances.

And just this week, the B.C. government officially cancelled Vancouver Coastal Health’s plan to open an overdose prevention site at 900 Helmcken Street, following an outcry of concern from nearby residents and businesses who worried about the potential disorder it might bring to their neighbourhood.

Dr. Vigo said that while “no one has died in a prevention site,” the impacts on the community “have not been established.”

“Whether that is a net benefit to the community, that is unclear, and that is something that needs much more scrutiny than it has had so far,” he said.