The strengthening association between youth cannabis use and psychological distress over time with André McDonaldThe strengthening association between youth cannabis use and psychological distress over time with André McDonald
Addiction Audio
Dr André McDonald discusses a decade of data on adolescent cannabis use and psychological distress in Ontario, highlighting stronger links among frequent users, especially girls. The conversation focuses on study methods, key findings, limitations, and implications for policy, prevention, and harm reduction messaging.
16:08•10 Apr 2026
Youth Cannabis, Mental Health, and Rising Distress: André McDonald on a Decade of Data
Episode Overview
- Psychological distress among Ontario secondary school students increased markedly between 2013 and 2023, while the association with cannabis use strengthened among the heaviest users.
- The study highlights that rising THC potency makes older research less relevant to what young people experience today.
- Additive interaction offers a more useful lens than multiplicative interaction for judging public health impact and guiding policy decisions.
- Frequent cannabis use among girls showed the strongest link with psychological distress, and 96% of the most frequent female users reported using cannabis to cope with mental health problems.
- Policy suggestions include reducing frequency of adolescent use, encouraging lower potency products, delaying age of initiation, and prioritising girls as a key subgroup for intervention.
“Whether or not it’s helping or harming their mental health, there’s not much evidence to support that it’s helping.”
Understand the complexities of addiction with insights from cutting-edge research on youth cannabis use and mental health. In this Addiction Audio instalment, public health researcher Dr André McDonald joins host Dr Elle Wadsworth to chat about his study on adolescent cannabis use and psychological distress in Ontario, Canada, from 2013 to 2023. Rather than opinion or scare stories, you’ll get clear data.
Using the Ontario Student Drug Use and Health Survey of 12–18-year-olds, André explains how his team looked at symptoms of depression and anxiety, cannabis use frequency, and how these patterns have shifted over a decade. One headline finding? Psychological distress jumped from 10.7% to 27.4%. At the same time, the link between cannabis and distress became stronger among the heaviest users.
André breaks down technical ideas in plain language, such as the difference between additive and multiplicative interaction, and why additive differences matter more for public health decisions. He also talks through a striking sex difference: “Among females who were using 40 or more times… there was a prevalence difference of 19%,” while for males there was little sign of a strong association.
A particularly worrying detail is that, in 2023, 96% of the most frequent female cannabis users said they used it to cope with mental health problems.
As André puts it, “Whether or not it’s helping or harming their mental health, there’s not much evidence to support that it’s helping.” You’ll hear honest discussion of the study’s limitations, including its cross-sectional design and the impact of COVID-19, along with clear, practical messages for policy and practice: reduce frequency of youth use, delay age of initiation, focus on lower potency products, and pay close attention to girls’ mental health and coping.
If you’re a clinician, researcher, parent, or simply curious about youth substance use and distress, this conversation gives you plenty to think about. How might these findings shape the way you talk to young people about cannabis?
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