The associations between cannabis use and anxiety, depression, and suicidality roughly doubled in strength from 2012 to 2022 in Canada, with frequent users showing up to 5.4 times higher prevalence of suicidality by 2022.
Mental health clinicians, public health officials, cannabis policy makers, parents, and anyone interested in cannabis and mental health trends.
What the researchers found
From 2012 to 2022, the prevalence ratio for weekly+ cannabis use (vs. no use) increased from 2.3 to 4.5 for generalized anxiety disorder, 3.0 to 5.2 for major depression, and 3.0 to 5.4 for suicidality — with strengthening associations particularly among youth and females for certain outcomes.
Why it matters
Both cannabis use and mental health problems have increased in Canada, but this study reveals that their association has also strengthened — meaning the mental health burden linked to cannabis may be growing faster than either trend alone would suggest.
The numbers in context
N=34,974 across 2 surveys; GAD PR: 2.3→4.5; MDE PR: 3.0→5.2; suicidality PR: 3.0→5.4 for weekly+ users; prevalence of GAD, MDE, and cannabis use approximately doubled from 2012-2022; youth suicidality up 44%
How the study worked
Comparison of two nationally representative Canadian cross-sectional surveys — CCHS-MH 2012 (n=25,113) and MHACS 2022 (n=9,861) — using Robust Poisson Regression to examine frequency-dependent associations between cannabis use and WHO-CIDI-diagnosed GAD, MDE, and suicidality.
What this study cannot tell us
Cross-sectional surveys cannot establish causality; 2022 data collected during pandemic aftermath may inflate mental health prevalence; potential confounding despite adjustment; diagnostic interview differences between surveys possible; cannot determine directionality.
How to read the evidence
Two large nationally representative surveys with validated diagnostic instruments provide strong ecological evidence, though cross-sectional design limits causal inference.
When this study was published
Published 2026; compares 2012 (pre-legalization) to 2022 (post-legalization and post-pandemic).
The bigger picture
In the post-legalization and post-pandemic era, the strengthening cannabis-mental health association demands urgent attention — particularly the dose-response relationship showing risks increase with frequency of use.
Questions still open
- Is the strengthening association driven by higher-potency products, more frequent use, or greater vulnerability in a post-pandemic population? Would longitudinal data confirm cannabis causing more mental health problems? Are treatment services keeping pace?
Common questions
Is the link between cannabis and mental health getting stronger?
Does cannabis use frequency matter for mental health risk?
Read the original research
Changes in Cross-Sectional Associations Between Cannabis Use and Anxiety, Depression, and Suicidality in a Nationally Representative Sample of Canadians From 2012 to 2022: Évolution des relations transversales entre la consommation de cannabis et la dépression, l'anxiété et les idées suicidaires au sein d'un échantillon représentatif de Canadiens à l'échelle nationale, de 2012 à 2022.
Canadian journal of psychiatry. Revue canadienne de psychiatrie, 7067437261420701
Citation
Halladay, Jillian; Ji, Chris; Georgiades, Katholiki; McDonald, André; Sunderland, Matthew; Slade, Tim; Chapman, Cath; MacKillop, James. (2026). Changes in Cross-Sectional Associations Between Cannabis Use and Anxiety, Depression, and Suicidality in a Nationally Representative Sample of Canadians From 2012 to 2022: Évolution des relations transversales entre la consommation de cannabis et la dépression, l'anxiété et les idées suicidaires au sein d'un échantillon représentatif de Canadiens à l'échelle nationale, de 2012 à 2022.. Canadian journal of psychiatry. Revue canadienne de psychiatrie, 7067437261420701. https://doi.org/10.1177/07067437261420701
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