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. 2022 May;239(5):1509-1519.
doi: 10.1007/s00213-021-06047-8. Epub 2022 Jan 12.

Prevalence and self-reported reasons of cannabis use for medical purposes in USA and Canada

Janni Leung  1   2 , Gary Chan  3 , Daniel Stjepanović  3 , Jack Yiu Chak Chung  3   4 , Wayne Hall  3 , David Hammond  5
Affiliations

Prevalence and self-reported reasons of cannabis use for medical purposes in USA and Canada

Janni Leung et al. Psychopharmacology (Berl). 2022 May.

Abstract

Rationale: There has been increasing attention on cannabis use for medical purposes, but there is currently a lack of data on its epidemiology.

Objectives: To examine the epidemiology of self-reported cannabis use for medical purposes by (1) estimating its prevalence, (2) comparing gender and age differences, and (3) investigating what reasons they were used to manage.

Methods: Participants included 27,169 respondents (aged 16-65) who completed Wave 1 of The International Cannabis Policy Study (ICPS) conducted across Canada and the USA in 2018 via online surveys. Cannabis policy conditions were "US legal-recreational" (legal for both recreational and medical uses), "US legal-medical only", "US illegal", and "Canada-medical only".

Results: The overall prevalence of self-reported ever cannabis use for medical purposes was 27%, with similar rates by sex and the highest prevalence in young adults. Prevalence was higher in US legal-recreational states (34%) than US illegal states (23%), US legal-medical only states (25%), and Canada (25%). The most common physical health reasons include use to manage pain (53%), sleep (46%), headaches/migraines (35%), appetite (22%), and nausea/vomiting (21%). For mental health reasons, the most common were for anxiety (52%), depression (40%), and PTSD/trauma (17%). There were 11% who reported using cannabis for managing other drug or alcohol use and 4% for psychosis.

Conclusions: A substantial proportion of the North American population self-reported cannabis use for medical purposes for a variety of medical reasons, including those living in jurisdictions without legal markets. Further research is needed to understand the safety and efficacy of these forms of medical cannabis use.

Keywords: Cannabis; Epidemiology; Legalisation; Marijuana; Prevalence; Therapeutic use.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Map of cannabis policy conditions at the time of the survey in 2018: “US–illegal”, illegal for recreational use and no legal medical market; “US legal–recreational”, legal for both recreational and medical; “US legal–medical only”, legal medical market, but illegal for recreational use
Fig. 2
Fig. 2
Prevalence of self-reported ever cannabis use for medical purposes by cannabis policy condition by a gender and b age groups (see Supplementary material S2 for data tables)
Fig. 3
Fig. 3
Weighted prevalence of reasons for which cannabis was ever used to manage, among people who self-reported cannabis use for medical purposes (see Supplementary material S3 for data tables)
See this image and copyright information in PMC

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