A new study prospectively identified risk profiles associated with patterns of problematic cannabis use in early adulthood. Participants were 1,229 individuals in the Great Smoky Mountain study. Between 1993 and 2015, they were assessed yearly from ages 9 to 16 years, as well as every 2-5 years from ages 19 to 30 years. This sample was representative of western North Carolina, except for oversampling American Indians. Problematic cannabis use was defined as either daily use or meeting full criteria for DSM-5 Cannabis Use Disorder (CUD). Patterns of problematic use included 1) non-problematic use in late adolescence (ages 19-21) and early adulthood (ages 26-30), 2) limited problematic use in late adolescence only, 3) persistent problematic use in late adolescence and early adulthood, and 4) delayed problematic use in early adulthood only. At each data collection point, participants were assessed for symptoms of psychiatric disorders and high-risk behaviors and were asked to report their cannabis use within the past three months. The authors ran multinomial logistic regression models to create relative risk ratios (RRRs) of risk factors between all patterns. Then, interaction models were used to test whether the effects of risk factors in the prediction of developmental patterns varied by race/ethnicity and sex. Results indicated 6.7% of the sample was classified as persistent problematic use (group #3 above), 13.3% as limited problematic use (group #2), and 3.7% as delayed problematic use (group #4). The persistent problematic use group was characterized by higher prevalence of anxiety disorders across development and more DSM-5 CUD symptoms during adolescence, compared to the limited problematic use group. The limited group had higher prevalence of externalizing disorders, maltreatment, and peer bullying in childhood, compared to the non-problematic use group, and greater childhood family instability and dysfunction than the persistent use group. There were no significant race/ethnicity or sex interactions observed.
Take away: In this sample, problematic cannabis use patterns during early adulthood had distinct risk profiles across development, with respect to psychiatric disorder symptoms and high-risk behaviors. There was no evidence of significant interactions of sex and race/ethnicity.