3 years after legalization, we have shockingly little information on how cannabis use and damage to health have changed


The three year anniversary of the legalization of recreational or non-medicinal cannabis in Canada comes on October 17th. It also marks the beginning of the Canadian government’s mandated health impact review.

Unfortunately, the slow roll-out of the Canadian retail cannabis market combined with the breakneck pace of academic research means that everything you and the government will hear about the health effects of legalization is based on outdated and often irrelevant data.

On October 17, 2018, non-medicinal cannabis became legal for recreational use in Canada.
THE CANADIAN PRESS / Jonathan Hayward

There are three major caveats to our understanding of the health implications of legalization.

First, almost all of the studies that looked at the effects of legalization on cannabis use and harm only looked at changes in the first year after legalization.

Yes, these results are reassuring: a small increase in cannabis use across Canada and a modest or no increase in emergency or hospital admissions for cannabis in Ontario, Alberta, and Québec. We must remember, however, that the transition from cannabis, which is illegal, to being widely available for legal purchase and use is not an overnight switch.

Remember, Ontario didn’t have a single legal cannabis store for the first six months after legalization, Québec only had 14, and the rest of the country didn’t do much better. The limited stores that were open often did not have much cannabis to sell due to severe product shortages.

But the retail cannabis market looks very different today. I lead a team that has followed the tremendous growth in the number of cannabis businesses since legalization. Our current data shows a more than 10-fold increase in branches between November 2018 and April 2021 (from 158 to 1,792).

At the same time, Canadians increased monthly spending on legal cannabis by 428 percent, from $ 1.80 to $ 9.50 per person aged 15 and over. Ontario currently has so many authorized cannabis stores – 1,175 of them – that experts are predicting major store closures.

A combined bar and line graph showing the number of cannabis stores and monthly legal cannabis spend in Canada

Number of cannabis stores and monthly legal cannabis spending in Canada between November 2018 and April 2021. Sales data from Statistics Canada and store data from Myran et al. 2021.
(Daniel Myran), Author stated

Statistics Canada data suggests that the maturing market may have an impact on all cannabis use. For the first year and a half after legalization, the legal market expansion largely corresponded to the illegal market contraction. However, since early 2020, the surge in legal sales has dramatically outpaced the decline in illegal sales, resulting in higher total spend.

Multi-line graph showing cannabis spending before and after legalization

Estimated quarterly spending ($ billion CAD) on medical and non-medical cannabis in Canada between January 2016 and June 2021. Net cannabis sales increased only 4.3 percent in the first year after legalization (Q3 2018 to Q3 2019), but increased by 32.4 percent by Q2 2021 (Q3 2018 to Q2 2021). Statistics Canada sales data.
(Daniel Myran), Author stated

Second, many types of cannabis products, including commercially made edibles like THC-containing candies, desserts, and beverages, didn’t go on sale until January 2020 in the United States. A study in Alberta reported an increase in cannabis poisoning among children after legalization. However, the study did not examine the period after commercial edibles were launched – the exact point in time when, based on the U.S. experience, we would expect the largest increases.

Oatmeal s'mores cannabis edibles, packaged and unpackaged, in the foreground, with a blurred man in the background

Edible cannabis products range from gummy candies to baked goods like these oatmeal s’mores, all of which could appeal to both children and adults.

So while recent studies show that there was no increase in damage in the first few months of a severely constrained and constrained retail market, we have almost no data on the health impacts of our current, far more mature, cannabis market.

What little we know is worrying. While the number of people who use cannabis almost every day in Canada did not increase much immediately after legalization, it rose 46 percent by the end of 2020 (5.4 percent in early 2018, 6.1 percent in early 2019, and 7.9 percent, respectively ). End of 2020).

An estimated 16.3 percent of Canadians aged 18 to 24 now report almost daily cannabis use, up 65 percent since legalization. Emergency room visits and hospital admissions for cannabis in Canada also increased eight and five percent, respectively, between 2019 and 2020.

That brings us to the third caveat. For anyone who thinks, “Wait a minute, what about the COVID-19 pandemic?” You’re right, that’s a big problem. More than half the time since legalization was during the pandemic.

There is no easy way to separate the impact of the pandemic of a maturing cannabis market on the recent surge in cannabis use. More data is to come – the federal government has invested millions of dollars in research – but we’ll have to wait to see those results.

The legalization of recreational cannabis, which has resulted in a significant reduction in social harm, such as highly discriminatory police charges of cannabis offenses, has had great public health benefits.

Three packs of cannabis chews with individual gums in orange, yellow and red each displayed below.

Edible cannabis soft chews look like candy. THC-containing candies, desserts and drinks were only offered for sale in January 2020.

My concern is that an increasingly commercialized cannabis market can lead to an increase in cannabis use and harm. Groups with financial interests in selling cannabis already claim that current regulations such as cannabis taxes, child-resistant packaging, and restrictions on cannabis advertising, including on social media, limit innovation. They argue that these need to be updated – that is, removed or reduced – in order to compete with the illegal market.

During the upcoming regulatory review, we need to remember that these regulations were put in place with care. Decades of alcohol and tobacco research and emerging cannabis-specific evidence suggest that these measures are very effective in reducing cannabis use among adolescents and young adults.

The federal government recommends that people start low and move slowly to avoid potential side effects from cannabis. The rapid expansion of the retail cannabis market over the past year is the regulatory equivalent of our country ingesting a very large cannabis edible for the first time. We have no idea how high we’re about to get. While we’re waiting to find out, having another edible is probably not a good idea.

My advice to the government during the upcoming review is to listen to its own recommendations and to take it slow with changes in cannabis regulations.