Impact of non-medical cannabis legalization with market restrictions on health service use and incident cases of psychotic disorder in Ontario, Canada

Authors

Kelly K. Anderson, Western UniversityFollow
Rebecca Rodrigues
Britney Le
Maliha Mamun
Suzanne Archie
Jordan Edwards
Tara Elton-Marshall
Jason Gilliland
Daniel Thomas Myran
Lena Palaniyappan
Christopher M Perlman
Jamie A Seabrook
Robin M Murray
Salimah Z Shariff

Document Type

Article

Publication Date

1-1-2024

Journal

International Journal of Drug Policy

Volume

123

First Page

104285

Last Page

104285

URL with Digital Object Identifier

https://doi.org/10.1016/j.drugpo.2023.104285

Abstract

BACKGROUND: Cannabis is a risk factor in the onset and persistence of psychotic disorders. There is concern that non-medical cannabis legalization in Canada may have population-level impacts on psychotic disorders. We sought to examine changes in health service use and incident cases of psychotic disorder following cannabis legalization, during a period of tight restrictions on retail stores and product types.

METHODS: We conducted a cross-sectional interrupted time-series analysis using linked population-based health administrative data from Ontario (Canada) from January 2014 to March 2020. We identified psychosis-related outpatient visits, emergency department visits, hospitalizations, and inpatient length of stay, as well as incident cases of psychotic disorders, among people aged 14 to 60 years.

RESULTS: We did not find evidence of increases in health service use or incident cases of psychotic disorders over the short-term (17 month) period following cannabis legalization. However, we found clear increasing trends in health service use and incident cases of substance-induced psychotic disorders over the entire observation window (2014-2020).

CONCLUSION: Our findings suggest that the initial period of tight market restriction following legalization of non-medical cannabis was not associated with an increase in health service use or frequency of psychotic disorders. A longer post-legalization observation period, which includes expansion of the commercial cannabis market, is needed to fully understand the population-level impacts of non-medical cannabis legalization; thus, it would be premature to conclude that the legalization of non-medical cannabis did not lead to increases in health service use and incident cases of psychotic disorder.

Notes

This is the author's version of the manuscript published in the International Journal of Drug Policy, available at https://doi.org/10.1016/j.drugpo.2023.104285

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