Assessment of cannabis use - Pediatric Research Foundation
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Assessment of cannabis use among Canadian adolescents after legalization

In Canada, the legalization of cannabis has led to greater accessibility to cannabis, an increase in cannabis potency, and the commercialization of a variety of cannabis-related products and devices. For example, over the past three years, rates of cannabis vaping among adolescents have doubled (from ~14% to ~28%). Therefore, there is a clear need for further studies to assess the mental health consequences associated with the current cannabis culture among Canadian adolescents.

The project aims to:

  1. Determine differences in clinical symptoms (depression, anxiety), cognition, and functional outcomes (academic and social performance) between adolescents who regularly use cannabis and adolescents who do not.
  2. Examine whether the method of cannabis administration (smoking or vaping) is associated with greater cannabis exposure (as measured by self-report and biochemical analysis) and worse clinical, cognitive, and functional outcomes.

This knowledge will be used to educate the public about the real harms associated with cannabis use in adolescence and may dispel myths that vaping is a safe alternative for cannabis use.

Number of children reached

This project will examine 90 adolescents over a two-year period (30 adolescents who smoke cannabis, 30 adolescents who vape cannabis and 30 adolescents who do not use cannabis).


Short-terms benefits :

After the study is completed, each participant will receive 10-15 minutes of cannabis education to highlight the risks and consequences associated with cannabis use during adolescence. The researchers hope that this knowledge will help individuals make informed decisions about their cannabis use.

Long-terms benefits :

The results of this study will provide new information on the association between cannabis use patterns (e.g., potency, method of administration) and critical mental health outcomes such as depression, anxiety, sleep and cognitive function. It will also determine how cannabis use affects academic achievement and social function.

Leverage effect

This project will lay the groundwork for future studies of cannabis use among adolescents at Douglas. The results will be used to apply for large-scale funding to conduct longitudinal studies, where adolescents who use cannabis will be followed over time. A prospective design will explore factors that predict escalation of cannabis use and track differences in clinical and neurobiological outcomes between cannabis users and non-users over time. Future funding will also include neuroimaging techniques to identify brain differences between adolescent cannabis users and non-users.


Principal researcher

  • Dr. Romina Mizrahi, Researcher and Assistant Professor


  • Douglas Research Centre, Douglas Mental Health University Institute, McGill University: Dr. Rachel Rabin
  • Icahn School of Medicine, Mount Sinai, New York, NY: Professor Muhammad Parvaz

Research Center

  • Douglas Research Centre, McGill University

Funded year


Project category

  • Neurodevelopment and mental health