Factors associated with health-related cannabis use intentions among a community sample of people who inject drugs in Los Angeles and San Francisco, CA 2016 to 2018

Objective: Cannabis motivations have been studied extensively among patients of medicinal cannabis dispensaries, but less is known about motivations in community samples of opioid-using people who inject drugs. Our objective is to describe cannabis use motivations associated with self-treatment of physical pain, emotional issues, and as an opioid substitute. Methods: Data come from 6-month follow-up interviews with people who inject drugs who participated in a study on the efficacy of an injection initiation prevention intervention in Los Angeles and San Francisco, California from 2016-18. The analytic sample consists of 387 people who inject drugs who reported past-month cannabis use. We developed multivariable logistic regression models by reported cannabis use motivations: physical pain relief, emotional problems, and opioid substitute. Results: The most common cannabis use motivations reported by people who inject drugs was to "get high," relieve physical pain and emotional problems, and reduce opioid use. In separate multivariate models, using cannabis for physical pain relief was associated with higher odds of using cannabis as a substitute for opioids; cannabis for emotional problems was associated with being diagnosed with depression; and cannabis as a substitute for opioids was associated with non-prescribed, non-injection methadone use. Conclusion: People who inject drugs reported using cannabis for health-related motivations. This motivation aligns with health needs and suggests the acceptability of cannabis use for health reasons in this population. Studies to determine the medical effectiveness of cannabis products for these common health and mental health needs among people who inject drugs are needed.