Use of psychedelics is on the rise in Canada. Doctors are starting to look at long-term risks, benefits

WARNING: This story mentions suicide.

People who take prohibited psychedelics such as psilocybin or LSD and go to the emergency department for care show a higher risk of death within five years compared with Canada's general population, a new study suggests.

Psychedelics are a subclass of hallucinogenic drugs.

In the last 10 years, use of drugs such as ketamine, psilocybin, ayahuasca, and MDMA or ecstasy increased in Canada and the United States. In the U.S., the percentage of people reporting they used hallucinogens more than doubled from 3.8 per cent in 2016 to 8.9 per cent in 2021.

Use varies widely, from microdosing psilocybin, the psychoactive ingredient in magic mushrooms as part of supervised treatment, to recreational use of the illegal substances.

Dr. Daniel Myran, a family physician and researcher at the University of Ottawa, recognized that in Canada, an estimated 5.9 per cent of people used a psychedelic such as psilocybin in 2023, with use as high as 13.9 per cent in people aged 20–24. It's a trend he sees among his own patients.

In Monday's issue of the Canadian Medical Association Journal, Myran and his team start to look at the potential long-term effects of using hallucinogens, specifically risk of death.

"We have a huge amount of hype and buzz about psychedelic-assisted therapy," Myran said. In psychedelic-assisted therapy, psychedelics such as psilocybin are combined with psychotherapy to treat post-traumatic stress disorder (PTSD) and treatment-resistant depression.

When Myran asks people in his practice why they're interested in psychedelics, some have the notion it'll help their mental health and that there aren't a lot of risks — but there's no clear proof that's the case, he says, given clinical trials exclude individuals who may be at higher risk of poor outcomes.

"I think that we just don't have that degree of data or certainty."

To better understand if there is an association between misuse of hallucinogens and increased risk of death, researchers looked at the subset of users who had interacted with the medical system, using health care data held by ICES, Ontario's health research institute. They examined emergency department visits, hospitalizations, and outpatient physician visits for more than 11.4 million people in Ontario aged 15 to 105.

Of the total group, 7,954, or less than one tenth of a per cent, sought acute care for hallucinogen use. 

The people who used hallucinogens and went to emergency were having bad reactions like uncomfortable hallucinations or a severe anxiety attack. "They are a group that's at really high risk and they probably merit close observation, interventions and thoughts about what can you do to reduce the risk," said Myron, who is also a public health and preventive medicine researcher with ICES.

Within five years, 482 (6.1 per cent) of people seeking acute care involving hallucinogens died, compared with 460 (0.6 per cent) of those in the general population of the same age and sex, the researchers reported.