Medical marijuana: Does research back up claims of therapeutic benefits?

A new Globe and Mail investigation is raising alarming questions about the safety of cannabis being sold illegally in unregulated dispensaries. But for the thousands of Canadians who use regulated and tested medical cannabis, there is another urgent issue researchers are scrambling to address: Does it work?

Background and regulations

Health Canada has not approved the use of medical cannabis, but a court ruling requires the government to “provide reasonable access to a legal source of marijuana when authorized by a health-care…