What is the prevalence and risk of cannabis use disorders among people who use cannabis? a systematic review and meta-analysis

Background and Aims: We aim to quantify the prevalence and risk of having a cannabis use disorder (CUD), cannabis abuse (CA) or cannabis dependence (CD) among people in the general population who have used cannabis. Method: We conducted a systematic review of epidemiological cross-sectional and longitudinal studies on the prevalence and risks of CUDs among cannabis users. We identified studies published between 2009 and 2019 through PubMed, the Global Burden Disease (GBD) Database, and supplementary searches up to 2020. The outcomes of interest were CUDs based on DSM or ICD criteria. Estimates were synthesized using random-effects meta-analyses, followed by meta-regression of study characteristics on effect sizes. Results: From 1383 records identified, 21 studies were included. Meta-analyses showed that among people who used cannabis, 22% (18-26%) have CUD, 13% (8-18%) have CA, and 13% (10-15%) have CD. Estimates from cohort studies, showed that the risk of developing CD increased to 33% (22-44%) among young people who engaged in regular (weekly or daily) use of cannabis. There was a lack of data from cohort studies to estimate the risk of CUD or CA among regular cannabis users. Conclusions: Cannabis users need to be informed about the risks of developing CUDs and the higher risks among those who initiate early and use frequently during adolescence. Future studies are needed to examine how changes in cannabis policies may affect the risks of CUDs in the population.