Conversations about cannabis in Canada

There are many conversations happening in our country related to cannabis. Two primary focuses of discussion relate to the medical use of cannabis, and the legalization of cannabis for recreational use. It is important to note that these two conversations, though related, have important distinctions. These two areas of cannabis use have very different intended outcomes and potential risks. This Perspective aims to characterize those differences by presenting the knowledge and evidence that distinguishes them.

Intended outcomes

Cannabis is a complex substance and contains over 100 cannabinoids, with the most information known about the effects of two, Tetrahydrocannabinol (THC) and Cannabidiol (CBD).

THC causes the psychoactive ‘high’ sought by recreational users. Several oral medications containing components with chemical structures similar to THC are currently being used to treat nausea and vomiting in specific medical conditions. CBD is the cannabinoid that has shown the most promise for medical purposes and is currently being studied for relief of symptoms and management of several medical conditions including epilepsy, anxiety, cancer, osteoarthritis, chronic pain and many others. Though there is growing study of its use, the majority of studies are focused on the adult population.

In Canada, most recreational cannabis has an average of 14 to 15 per cent THC, however, it can contain up to 30 per cent. Recreational cannabis has little to no CBD. CBD does not have psychoactive effects.

According to statistics Canada, 42 per cent of males aged 15 to 24 and 39 per cent of females aged 15 to 24 report using recreational cannabis at least once in their lifetime. Further, according to the Ontario Student Drug Use and Health Survey (OSDUHS), 19 per cent of students in grades 7 to 12 report having used recreational cannabis at least once in the past year. It is also estimated that one per cent of these students report daily cannabis use.  

Though evolving, there is currently limited scientific evidence of the effectiveness of medical cannabis to manage symptom relief for children and youth. Currently, cannabis is a controlled substance and is not an approved pharmaceutical in Canada; however, some patients may seek authorization to legally use it under the Access to Cannabis for Medical Purposes Regulation (ACMPR). Due to the many complexities of tracking and studying medical cannabis use, it is not widely known how many children and youth access cannabis for medical purposes in Canada at this time.

This medical cannabis authorization process involves receiving a form which is completed by a medical provider as per Health Canada guidelines. Authorized individuals may then receive a cannabis supply from an authorized licensed producer or grow a small amount for their own personal use. Like recreational cannabis, medical cannabis can be consumed in several forms such as smoking, vaping, eating or consuming through oil preparations. Children and youth accessing medical cannabis often use cannabis oil which contains very low to no THC and greater concentrations of CBD.

Increasingly, anecdotal reports indicate that patients and caregivers attribute significant symptom relief to the use of medical cannabis. In some circumstances, patients with severe epilepsy have seen a reduction in seizure activity, significantly improving their quality of life.

Despite cannabis legalization later this fall, it is anticipated that the recreational and medical structures will remain separate as they are now. Further to this, the legal allowable age for recreational cannabis use in Ontario is slated to be 19 years of age.

Potential risks

The use of recreational cannabis, particularly THC, is associated with concerns regarding brain development, cannabis use disorder and onset of psychosis. Structural differences in the brain are seen in youth who use recreational cannabis regularly. These changes show lower brain volumes, different folding patterns and thinning of the cortex, less neural connectivity and lower white matter integrity, all of which may lead to decrease in attention, memory impairments, and decreases in other executive functions such as higher-level problem solving. It is important to note that these brain changes are most remarkable the earlier in age that cannabis use is started. It is reported that five to nine per cent of people who use cannabis will develop dependence, and for those who start using cannabis during adolescence this increases to 17 per cent (one in six).

There is scientific evidence of a strong relationship between the use of cannabis and mental illness, largely attributed to the effects of THC. Regular use of cannabis prior to the age of 18 has been associated with the emergence of psychosis. Some individuals go on to receive a diagnosis of schizophrenia, however it is likely that these individuals had an existing genetic risk. For this group, the use of cannabis exacerbates symptoms and the course of the illness.  

Acute risks of cannabis use relevant for teens (and others who use recreational cannabis) relate to driving while under the influence (again linked to the THC component of cannabis). Cannabis use has been shown to impair judgment, motor coordination, and reaction time in studies examining this effect. Of concern is that one in 10 drivers in Grades 10 to 12 report driving a motor vehicle after using cannabis (OSDHUS 2015).

SickKids' position

Complexity in understanding how patients use both recreational and medical cannabis can pose challenges for health-care providers. To date, many of the known risks of cannabis use are attributed to recreational use. With the upcoming legalization, researchers are hopeful that there will be better access to promote more rigorous study of the effects of both recreational and medical cannabis for all ages.

Health-care organizations are poised to help health-care providers understand the differences between recreational and medical cannabis use, identify the needs of individual patients and promote practices, which support access to appropriate resources when needed.

SickKids has developed an approach as it relates to the administration of legally authorized medical cannabis to accommodate patient needs while staying within the limits of the regulation and prioritizing safety. Appreciating cannabis as a complex substance, interpreting cannabis and health-care provider regulations, and understanding the stigma and political landscape surrounding its use in Canada are critically important to provide comprehensive support for patients, families and health-care providers. At SickKids, our approach gives clinical teams the tools they need to manage continuing the use of medical cannabis during a patient's hospital stay while balancing the unique needs of the individual.

See recommendations from the Canadian Paediatric Society.