Illicit drug use and prescription drug misuse among young adult medical cannabis patients and non-patient users in Los Angeles.

Introduction: Young adults have the highest rates of cannabis and other drug use, as compared to other age groups, and contribute a significant proportion to the total population of medical cannabis patients (MCP). However, little is known about the relationships between various cannabis practices and illicit drug use/prescription drug misuse among young adult cannabis users with and without legal access to medical cannabis.

Methods: 210 MCP and 156 non-patient cannabis users (NPU) aged 18-26 were recruited in Los Angeles in 2014-15 for a longitudinal study assessing the impact of medical cannabis on health and substance use among emerging adults. For the present analysis, only quantitative baseline survey data were used. Logistic regression was used to examine the associations between past 90-day cannabis practices and other drug use, including illicit drug use and prescription drug misuse.

Results: Illicit drug use was associated with being non-Hispanic white (AOR = 3.0, 95% CI 1.8-5.1), use of cannabis concentrates (AOR = 2.8, 95% CI 1.6-4.9), while self-reported medical cannabis use was associated with lower probability of illicit drug use (AOR = 0.5, 95% CI 0.3-0.9). The odds of prescription drug misuse were increased for participants who reported use of cannabis edibles (AOR = 2.0, 95% CI 1.1-3.5), and decreased with age (AOR = 0.9, 95% CI 0.8-1.0) and for those who used cannabis alone (AOR = 0.5, 95% CI 0.3-0.9).

Conclusion: Use of alternative cannabis forms, but not cannabis use frequency, were associated with greater odds of other drug use. Self-reported medical cannabis use, but not MCP status, decreased probability of illicit drug use.