Canada Took the Leap on Legal Weed—Five Years Later, No Meltdown

While some US states have decriminalised recreational cannabis use, Canada fully legalised. Meanwhile, here in NZ, outside medical use the hash remains illegal. 

So how has Canada's legalisation gone? Jeffrey Singer reports in this guest post.

Canada Took the Leap on Legal Weed—Five Years Later, No Meltdown

Critics warned it would lead to widespread abuse. Yet, in October 2018, Canadian lawmakers made Canada the first G7 country to legalise, not merely decriminalise, recreational cannabis.

Researchers at McMaster University have conducted a prospective cohort study involving 1,428 adults in Hamilton, Ontario. Some participants were cannabis consumers before legalisation, while others began using cannabis post-legalisation, between September 2018 and October 2023. Their findings were published today in the Journal of the American Medical Association. The results:

Cannabis use frequency increased modestly in the 5 years following legalisation, while cannabis misuse decreased modestly.

During the COVID-19 pandemic, alcohol, cannabis, and illicit substance use spiked in most countries. Researchers found that after the pandemic’s onset, cannabis misuse (or cannabis use disorder) experienced a sharp reduction and has not yet returned to prior rates. The most significant drop occurred among individuals who were frequent users before legalisation.

Overall, during the study period, individuals who frequently used cannabis before legalisation tended to reduce their consumption, while those who had not previously used cannabis were more likely to increase their use. Misuse declined among all groups that were already using cannabis before legalisation. Researchers observed a rise in misuse among those who had previously abstained—an expected outcome given their zero-use baseline.

Further analyses identified significant changes in the types of cannabis products favored by active users over time, with declines in the use of dried flower, concentrates, cannabis oil, tinctures, topical ointments, and hashish. In contrast, the consumption of edibles, liquids, and cannabis oil cartridges or disposable vapes increased. The shift away from combustibles is a positive development that may reduce the likelihood of developing pulmonary health issues.

These findings suggest that cannabis legalisation may not lead to the adverse health effects that critics feared. In fact, it could promote safer consumption habits and minimise overall harm.

Canada’s experience did not result in a public health crisis. Misuse declined, safer products gained acceptance, and the situation remained stable. As US states continue to consider legalisation, the takeaway is clear: the question isn’t whether to legalise—it’s how to do it smart.

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Jeffrey A. Singer is a senior fellow at the Cato Institute, working in the Department of Health Policy Studies, and has been in private practice as a general surgeon for more than 35 years.
    He is also a visiting fellow at the Goldwater Institute in Phoenix, and a member of the Board of Scientific Advisors of the American Council on Science and Health. From 1994 to 2016, he was a regular contributor to 'Arizona Medicine,' the journal of the Arizona Medical Association. He writes and speaks extensively on regional and national public policy, with a specific focus on the areas of health care policy and the harmful effects of drug prohibition.

    His post first appeared at the Cato at Liberty blog.