National Website Designed to Educate Emerging Adults about Risks of Cannabis

With this summer’s planned legalization of recreational cannabis use, mental health clinicians and researchers are deeply concerned that young Canadians may be unaware and unprepared for the effects of cannabis on the developing brain. Approximately 15% of Canadians – including roughly 30% of adolescents and young adults – report using cannabis in the past year. Dr. Phil Tibbo, President of the Canadian Consortium for Early Intervention in Psychosis stated, “Schizophrenia can develop up to six years earlier in young people who consume cannabis regularly.”

Nearly 1% of the population will develop schizophrenia, which affects a person’s ability to discern reality from non-reality, with young men typically developing the illness in their late teens, while young women often develop it in their early-to-mid 20s. Research has indicated that cannabis use can play a role in early onset of psychotic disorders.

Brain receptors and neurotransmitters can be altered by the amount of THC, which impacts the development of the brain. As well, the strength of the main mind-altering or psychoactive ingredients found in cannabis today is much more potent than it was decades ago. THC counts have increased from 1.5% in 1970 to 28% in 2018. Dr. Candice Crocker, Assistant Professor at Dalhousie University, Department of Psychiatry remarked that the risk of developing psychosis in youth is amplified by up to twelve times with use of high THC prior to age 15 and is greater for people under 25-years of age. “We know from advanced medical imaging that the human brain keeps developing until age 25. The last part of the brain to develop is the part most involved in planning and controlling our emotions. If you have ever watched a teenager and wondered why they can’t seem to plan or see the possible consequences of their actions, it’s because that is the part of the brain that needs to be mature for them to be able to do these tasks. This is also part of the brain that is most affected in psychosis. This final developmental process is controlled by the cannabis receptor system using cannabinoids that your body makes. If the brain is flooded with extra cannabis chemicals, such as from using cannabis, the brain may not develop correctly. This is the underlying biological process we believe is behind the increased psychosis risk for youth with cannabis use.”

A new national harm-reduction website is aiming to educate youth with balanced information about the link between cannabis use and psychotic disorders like schizophrenia. Cannabis and Psychosis: Explore the Link ( is a project of the Schizophrenia Society of Canada. Featuring current scientific evidence and young people’s experiential perspectives, the resource dispels some of the myths about cannabis while empowering youth and emerging adults with education and prevention resources they need to have an informed understanding about the risks of cannabis use.

Catherine Willinsky, Project Manager at the Schizophrenia Society of Canada emphasized that conversations about cannabis happen everywhere, in families, schools, among friends, in therapeutic settings and elsewhere. The goal of this resource is to provide accurate information that will resonate with youth across Canada. Willinsky said, “Beginning in 2009, we worked with young people to learn about their questions and potential risks posed by cannabis use, and their own experiential perspectives. She added, “This participant-action research project engaged youth in early intervention and psychosis clinics throughout Canada. The information they generated shed light on the reasons why young people use, their lived experiences, and what they felt was important to communicate to other youth about key issues around cannabis and psychosis. This new resource combines their insights with updated scientific evidence to create a balanced, non-judgemental and accessible source of information that we hope will be helpful for youth as they make their own decisions about cannabis use.”

One of the participants in the study and a survivor of schizophrenia, Laura Burke, commented that having an online platform geared to emerging adults is a powerful tool to help educate at-risk-youth about the real risks of cannabis use and psychosis. “I grew up in a small town where many kids were drinking in junior high school. Ironically, I was concerned about alcoholism, so I drank less alcohol, and replaced alcohol use socially with marijuana. I don’t know for sure whether early marijuana use impacted my development of schizophrenia later, but if I had known the connection, I might have made a different decision.” Burke added, “This project will help relay information on potential risks of early cannabis use in a respectful and engaging way, so youth feel empowered to make informed choices about their health, and their futures.

Some of the key research findings integrated into the ‘Cannabis and Psychosis: Explore the Link’ website:

  • The median age of starting cannabis use was 17-years-old for both males and females in 2015.
  • Cannabis use impacts psychosis which is a break from reality characterized by hallucinations, delusions, impaired thinking and lack of motivation.
  • Regular cannabis use can impact the development of a chronic life-long psychotic disorder in at-risk individuals and is associated with an earlier age of onset of psychosis.
  • Cannabis use can prevent or hinder recovery in individuals already diagnosed with a psychotic disorder.
  • THC content has increased from 1.5% in 1970 to 28% in 2018.

Project supporters and partners:

“We appreciate and value the collaborative partnership with the Canadian Consortium for Early Intervention in Psychosis in assisting the Schizophrenia Society of Canada in the evidence review required for this project,” states Chris Summerville, CEO of Schizophrenia Society of Canada. We would also like to thank the Substance Use and Addictions Program of Health Canada, and the Canadian Centre for Substance Use and Addictions for their generous financial support of this project.

The opinions and interpretations in this website are those of the authors and do not necessarily reflect those of the Government of Canada.

For more information, please contact:
Dr. Chris Summerville
Chief Executive Officer
Schizophrenia Society of Canada
Office: (204) 786-1616, Mobile: (204) 223-9158

Dr. Phil Tibbo
Chair, Schizophrenia Society of Canada Foundation
Office: (902) 473-1678


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