Trajectories of cannabis use and risk for opioid misuse in a young adult urban cohort

Background: Although much of the attention surrounding the opioid epidemic has focused on rural and suburban Whites and prescription opioids, heroin overdoses among urban Blacks are on the rise. While some argue that legalization of cannabis will combat the epidemic, there are concerns it ignores the shift in the epidemic and could increase vulnerability to opioid misuse. The goal of this study is to examine the association between cannabis use from adolescence to young adulthood with opioid misuse in a primarily urban Black cohort. Methods: Data are from a study of 580 youth (87 % Black and 71 % low SES) residing in Baltimore City followed from ages 6−26. Cannabis trajectories were identified between ages 14–26 using group-based trajectory modeling. Logistic regressions were conducted to examine the impact of trajectories on opioid misuse in young adulthood adjusting for individual, neighborhood and peer factors. Opioid misuse was defined as using heroin or narcotics or painkillers without a prescription between ages 19–26. Results: Four cannabis trajectories were identified: Low/Non-Users (59.7 %), Adolescent Onset Limited (19.5 %), Young Adult Onset (10.8 %), and Adolescent Onset Chronic (10.0 %). Adolescent Onset Chronic cannabis users had the highest rate of opioid misuse (44.8 %) followed by Adolescent Onset Limited (18.8 %), Young Adult Onset (14.8 %) and Low/Non-Users (8.3 %). Prevalences were significantly higher for Adolescent Onset groups relative to Low/Non-Users even after adjustment for individual, neighborhood and peer factors. Conclusions: Adolescent onset cannabis use is associated with opioid misuse in young adulthood among urban Blacks even after adjustment for socioecological factors associated with opioid misuse.