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