Canadian Centre on Substance Use and Addiction

Presentation to the Senate Standing Committee on Social Affairs, Science and Technology, Study of Bill C-45, Canadian Cannabis Act

Speaking Notes for Dr. Amy Porath Canadian Centre on Substance Use and Addiction

Senate Standing Committee on Social Affairs, Science and Technology, Study of Bill C-45, Canadian Cannabis Act
Ottawa, Ontario, April 16, 2018


Good afternoon Mr. Chair and members of the Committee. My name is Amy Porath and I am the Director of Research at the Canadian Centre on Substance Use and Addiction, or CCSA. CCSA was created in 1988 and we are Canada’s only agency with a legislated national mandate to reduce the harms of alcohol and other drugs on Canadian society.

We welcome the opportunity to speak to you today about Bill C-45. Cannabis has been a priority area of focus for our organization since 2008 and we have demonstrated our subject-matter expertise through our research publications and our work with national and international partners on the health and social impacts of cannabis use, drug-impaired driving, and regulatory options.

To respect time constraints, my presentation today will be brief and will focus on the health effects of non-medical cannabis, as well as the importance of evidence-based public education. Should the Committee wish, CCSA would be pleased to speak to other areas related to the Bill at another date.

Health Effects

Canadian youth have among the highest rates of cannabis use in the world, and despite a decrease in use in recent years, cannabis remains the most commonly used illegal drug among Canadians aged 15 to 24.

These young adults are more than twice as likely to have used cannabis in the past year as compared to adults aged 25 and older. Youth are also at greater risk of experiencing cannabis-related harms because adolescence is a time of rapid brain development. The risks associated with use increase the earlier youth begin to use cannabis, along with the frequency of use and quantity of cannabis that is consumed. Delaying the start of cannabis use, as well as reducing the frequency, potency and quantity used, can reduce this risk.

From the research, we also know that cannabis use affects cognitive functioning, including attention span, learning and decision making. Chronic or regular cannabis use has been associated with mild impairments of memory, attention and other cognitive functions, and it is uncertain how reversible these impairments are once cannabis use has stopped.

There is also consistent evidence that cannabis use impairs the ability to safely operate a motor vehicle. It doubles the risk of collisions, and the risk increases further when cannabis is mixed with even small amounts of alcohol.

With respect to mental health, there is consistent evidence that regular use during adolescence is associated with an increased risk of experiencing psychotic symptoms or schizophrenia, especially when there is a family history of such disorders. While there is emerging research indicating a relationship between chronic cannabis use and other mental health outcomes, such as depression, anxiety and suicidal behaviours, we need more research to better understand the nature of these relationships.

We also know that continued, frequent and heavy cannabis use can result in physical dependence and addiction. Youth are especially vulnerable given their ongoing brain development. It is estimated that approximately 1 in 11 (9%) of those who use cannabis will experience dependence. This rate increases to 1 in 6 (17%) for those who begin use during adolescence and is as high as 1 in 2 for those who use cannabis daily or near-daily.

While there is certainly a lot we know about the health effects of non-medical cannabis use, there remain significant gaps in our current knowledge, which demonstrates the need for ongoing investment in research, particularly on the effects on youth. That’s why the Government of Canada’s timely investment of $10 million dollars in Budget 2018 for CCSA to further study the impact of cannabis use is so important as Canada moves towards legalization.

Importance of Public Education

I also want to briefly emphasize the importance of a comprehensive, evidence-based approach to public education and prevention to provide Canadians, especially youth, with the knowledge and skills they need to make informed decisions about cannabis use.

A comprehensive approach involves programming in and after school, resources for parents, families and communities, and earned and paid media, to help educate about cannabis use to achieve the best outcomes. It also requires ongoing investment, as well as monitoring and evaluation to ensure that it is having the desired impact.

CCSA is a research-generating organization and we have conducted focus groups with Canadian youth to understand their perceptions of cannabis and cannabis use. They told us that they want information about cannabis that is fact-based, as opposed to fear-based. For example, they want to know exactly how cannabis use and the level of consumption might impair their ability to drive a vehicle. They also told us they want to hear harm reduction strategies so that they are knowledgeable on how they can reduce the risks if they do decide to use cannabis. To that end, education and prevention initiatives need to incorporate what we heard from Canadian youth in order to have an impact.

Young Canadians also said they want information from sources they trust who can speak credibly about cannabis. Depending on age, these information sources could include parents and educators, but perhaps most importantly, it includes peers. To achieve this goal requires training, resources and consistent messaging for youth allies, such as teachers, counsellors, youth service providers or healthcare practitioners, to help them engage in these conversations. CCSA is currently proactively engaged in the creation of a cannabis communications guide, which will be launched in the coming months, to provide just this type of resource.

It is also important to include targeted messaging about high-risk cannabis use to assist young people in making informed decisions. This messaging includes information about the effects of frequent and heavy use, about use at an early age or in combination with other substances; and about use by youth with mental health conditions and young women who are pregnant.


In closing, I would like to emphasize the importance of providing sustained investments in research, public education, and prevention efforts to support the successful regulation of non-medical cannabis use.

I would like to thank the Committee for the opportunity to speak today and will be pleased to answer your questions.

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