Canadians are mostly in favour of legalising marijuana. Credit: Flickr.

The Prime Minister of Canada, Justin Trudeau, spoke out clearly in favour of legalizing marijuana during the election campaign that brought him to power on October 19. Professor Serge Brochu of University of Montreal's School of Criminology would support this policy change and has answered several questions to clarify the rational and nuance surrounding his opinion.

Q: What are the arguments in favour of legalization?

S.B: It will transform a black market into a legal industry that is taxable and supported by a quality control system. Criminal groups make huge profits from the sale of marijuana, and these profits have no benefit to society. Moreover, the negative effects of prohibition are well documented. For example, 54% of marijuana-related arrests are for simple possession. In my opinion, this represents a waste of police resources. Moreover, in many cases, young people are faced with a criminal record at an early age. In fact, regular cannabis users are often ordinary people who smoke at home and are never arrested. This is what we found in a study conducted among 165 regular cannabis users in 2011 and published in the Journal of Drug Issues.

We should not delude ourselves. Many people smoke marijuana; they always have and they always will. Legalization will only make their use transparent. If marijuana is legalized, we'll be able to openly conduct research on the phenomenon: What is normal, moderate use? How do we measure our ownTHC level (or tetrahydrocannabinol, the psychoactive substance in cannabis)?

Q: Are Canadians ready?

S.B.: Yes, much more than we think. Surveys have shown that Canadians agree on a form of decriminalization. According to an Ekos-La Presse survey published on November 3, 2015, two in three Canadians are in favour of legalizing marijuana. Though not a scientific tool, CBC's Vote Compass showed this support at nearly 90%. During the last federal campaign, all the major party leaders, with the exception of Stephen Harper, were for decriminalization or legalization.

Q: Are there model countries or laws? Should we follow the example of Holland?

S.B.: In Holland, marijuana is decriminalized, but the production chain is still largely controlled by the black market. In Uruguay, marijuana is legalized and the black market is losing ground, but it is still too early to draw conclusions because the sale in pharmacies has been postponed. In the United States, Colorado, Washington, Alaska, and Oregon have legalized marijuana, and these are interesting cases. But it's a bit different from what we would find in Canada, if I go by the recommendations of Senator Pierre Claude Nolin, who, in 2002, signed a well-documented report on the subject. Previously, Marie-Andrée Bertrand, who worked at the University of Montreal, also concluded in the benefits of legalization.

Q: And what do these reports recommend?

S.B.: Legalization may come with increased use, so well before allowing the commercialization of marijuana, we must put into place well-defined prevention and addiction treatment programs. We must think prevention, and public health experts must be involved.

It may seem paradoxical, but it's the same thing for alcohol. Prohibition created multiple problems that are much easier to address when distribution and use are legal.

Q: Should there be a minimum legal age for using cannabis?

Yes, but studies have shown that a large majority of young people have tried smoking marijuana at least once. If we limit the sale and use of cannabis to 21 years of age, as some have suggested, the problem of illegal supply would fall squarely on the shoulders of younger people. It is therefore important that the legal age for buying marijuana not be too high.

Q: Do you think Justin Trudeau will keep his election promise?

I hope so, but given the number of measures that have to be put in place before legalizing marijuana, I don't think it'll happen right away. I think Trudeau will wait one or two years as head of government before launching such an innovative project. That said, Canada is a step ahead of many countries since it has authorized the use of medical marijuana, a measure introduced in 2001 that has worked quite well.

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More information: S. Brochu et al. "There's what's on Paper and then there's What Happens, out on the Sidewalk": Cannabis Users Knowledge and Opinions of Canadian Drug Laws, Journal of Drug Issues (2011). S. Brochu et al. "There's what's on Paper and then there's What Happens, out on the Sidewalk": Cannabis Users Knowledge and Opinions of Canadian Drug Laws,(2011). DOI: 10.1177/002204261104100105