The prevalence of cannabis use disorders in people who use medicinal cannabis: a systematic review and meta-analysis

Background: The recent and unprecedented utilisation of cannabinoids for medicinal reasons has given rise to concerns about the development of cannabis use disorders within this population. Cannabinoids are being widely used in general practice and psychiatry, despite a clear understanding of the potential impact on psychiatric disorders and the development of cannabis use disorders. The prevalence of cannabis use disorders (CUDs) in people who use cannabis recreationally has been estimated at 22%, yet there is a dearth of literature exploring CUDs among people who use medicinal cannabis. We aimed to systematically review the prevalence of CUDs in people who use medicinal cannabis. 

Methods: In our systematic review and meta-analysis, we followed PRISMA guidelines and searched three databases (PsychInfo, Embase and PubMed) to identify studies examining the prevalence of CUDs in people who use medicinal cannabis. Meta-analyses were calculated on the prevalence of CUDs. Prevalence estimates were pooled across different periods (recent use and 6-12 months) using the DSM-IV and DSM-5. 

Results: We conducted a systematic review of 14 eligible publications, assessing the prevalence of CUDs with three diagnostic criteria, providing data for 3681 participants from five different countries. The systematic review demonstrated that demographic factors, mental health problems and the management of chronic pain with medicinal cannabis were associated with an elevated risk of CUDs. A meta-analyses was conducted on the prevalence of CUDs. For individuals using medicinal cannabis in the past 6-12 months, the prevalence of CUDs was 29% (95% CI: 21-38%) as per DSM-5 criteria. Similar prevalence was observed with DSM-IV (24%, CI: 14-38%) for the same period. 

Conclusions: The prevalence of CUDs in people who use medicinal cannabis is substantial and comparable to people who use cannabis for recreational reasons, emphasizing the need for ongoing research to monitor the prevalence of CUDs in people who use medicinal cannabis. The review highlights a developing concern which requires thoughtful attention in the areas of public health, policymaking, and clinical practice.