On October 20, marijuana will no longer be an illegal drug in Canada—a move that could make it much easier to study how cannabis affects the body and the brain.

“Cannabis has risks and maybe benefits,” says M-J Milloy, an infectious disease epidemiologist at the British Columbia Centre on Substance Use and the University of British Columbia who studies HIV patients’ illicit drug use. Under prohibition, however, “what we, as scientists, have not been able to do is try to figure out what those risks and benefits are in an open way,” he says. “The hope is that legalization of cannabis will take the shackles off scientific inquiry and will allow us to ask and answer the sort of questions we should have been asking twenty, thirty, forty years ago.”

Currently in Canada, to study the physiological effects of cannabis in humans, researchers have to apply for an...

But with legalization on the horizon, studies into its effects on health are even more critical, and funders apparently agree, infusing more money into cannabis research. The trouble is that while consumers will be able to easily buy pot, scientists still face restrictions on how they can study it.

A legacy of restricted research on marijuana

Despite widespread use and anecdotal evidence to support marijuana’s benefits, researchers don’t have a concrete grasp on how exactly cannabis interacts with the chemistry and physiology of the brain. Basic research on the endocannabinoid system—identified in the 1980s—has been ongoing in Canada for several decades, notes Nina Cluny, a pharmacologist at the Canadian Institutes of Health Research (CIHR), in an email to The Scientist. She is leading the implementation of the cannabis research effort at CIHR, which is focused on studying the biological and social impacts of cannabis legalization and regulation. The “illicit nature of cannabis,” she says, “has limited our knowledge of the effects of cannabis as a whole.”

Getting insight into marijuana’s effects from Canada’s neighbors to the south hasn’t been productive either. The U.S., too, has made it difficult for scientists to study the plant and its various phytochemicals.

In a June 2017 letter to the Canadian federal government, Milloy and other scientists describe exactly how cannabis prohibition has hindered research and how that lack of research could affect legalization. “[S]ubstantial knowledge gaps remain related to the potential consequences of legalized cannabis use,” the signatories write, arguing that the government needed to develop avenues for researchers to “produce, possess, and use cannabis and cannabinoids for research purposes” and “create and support dedicated and distinct funds for medical and non-medical cannabis research.”

A few years ago, the Canadian government modified its regulation of medical marijuana, making it easier to access, and the same could have been done for research, but it didn’t happen, Milloy says. That said, some scientists, such as McGill University’s Mark Ware and the University of California, San Francisco’s Donald Abrams, “by sheer force of personality,” have been able to do preliminary studies on cannabis use, particularly for treating pain and for managing HIV infections, Milloy says. That work has helped to reveal more details about the endocannabinoid system, which plays a role in appetite, mood, and memory. 

Legalization “offers a new opportunity to address gaps in our knowledge, such as the effects of cannabis use on brain development, mental health, or other health outcomes, and it will broaden our knowledge of the potential benefits of cannabis for conditions such as pain,” Cluny says. It could also allow scientists to do much larger clinical studies, Milloy adds. 

Yet even with legalization on the way, research regulations haven’t changed. As it is, scientists still have to apply for an exemption to conduct cannabis research. Health Canada, the country’s national public health agency, did post a statement on June 28 with information on upcoming rules changes that should make it easier for researchers to grow, process, and possess cannabis, although the rules apply mainly to agricultural science, not public health and basic research.

More money, more science 

Analysts estimate that a legal cannabis market could become a $5-billion to $6-billion industry in Canada, with some of that money funneled toward research, Milloy notes. CIHR, the equivalent of the National Institutes of Health in the U.S., has invested more than $20 million CAD in cannabis-related research in the last five years, Cluny says. In December 2017, the agency awarded $1.4 million CAD to researchers to study how recreational legalization will influence public health, including exposure to second-hand marijuana smoke and the effects of use during pregnancy. “Going forward, CIHR will soon be launching a new funding opportunity to further build cannabis research capacity,” Cluny says, noting details would be posted in the next few days on CIHR’s website.

New pockets of money are opening, says Hathaway, who has been surveying marijuana users for over two decades, trying to understand the different populations of people who use the drug. But there’s a catch. Federal dollars, he says, are now being awarded to multidisciplinary teams, which could squeeze out researchers working in the field on a smaller scale, or those seeking answers about the cultural ramifications of cannabis use or other topics not directly related to public health. 

“Corporate research will also enter the arena,” he says, which could lead to conflicts of interest for scientists taking company money. “I am not saying any of this is good or bad, it’s just where the field is going,” Hathaway says.

The University of British Columbia, for example, received a substantial gift from Canopy Growth Corporation to study how cannabis might be developed into a tool to mitigate the risk of opioid overdose. “We aren’t testing their candidate molecule or strain,” Milloy notes, explaining the gift is kept at “arm’s length,” so scientists can run their experiments independent of the company’s influence. Still, he concedes there is cause for some concern about private corporations “encroaching on academic integrity and freedom.” 

Despite the concerns about the research to come, legalization has pushed more and more investigators to join the field. “There’s going to be a lot of research into many different facets of cannabis use,” notes Benedikt Fischer, a criminologist at Simon Fraser University.

“Will Canada will be a world leader in cannabis research, I certainly hope so,” Milloy adds. “But I also hope that colleagues outside Canada, in the U.S., England, in France and Uruguay are involved, too. Us Canadians, we want to lead the way, but we don’t want to be alone.”

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