Psychiatric comorbidity in adolescent use and poly-use of combustible, vaporized, and edible cannabis products.

Cannabis legalization and commercialization has resulted in novel alternative cannabis products on the market, including edible and vaporized cannabis, which may appeal to youth with psychiatric problems. Psychiatric comorbidity in adolescent use and poly-use (i.e., use of >2 products) of combustible, edible, and vaporized cannabis products has largely gone uninvestigated. This 2015 cross-sectional survey of Los Angeles, California area adolescents (Mage = 16.1, N = 3177) characterized associations of various psychiatric problems with use and poly-use of combustible, edible, and vaporized cannabis. Exposure variables included past 30-day non-cannabis substance use (alcohol, e-cigarettes, combustible cigarettes, and nonmedical prescription opioid and stimulant use; yes/no), and psychiatric problems including past-week depressive symptom frequency, past 6-month ADHD symptom and conduct problem frequency, anhedonia, and five dimensions of impulsivity (sensation seeking, perseverance, lack of premeditation, positive urgency, and negative urgency). Outcome variables included past 30-day use (yes/no) of combustible, edible, and vaporized cannabis, independently, and number of cannabis products used (single, dual-use, poly-use). Results showed that all forms of non-cannabis substance use (ORs range: 13.7-36.1) and all psychiatric symptoms and traits (ORs in SD units range: 1.1-2.1) were positively associated with combustible, edible, and vaporized cannabis product use. The magnitude of comorbidity did not significantly differ by cannabis product type used in most cases. Psychiatric comorbidity was typically stronger in poly-product than single-product cannabis use and greater for externalizing-type than internalizing-type psychiatric problems. Practitioners, policy makers, and scientists should be aware that pervasive psychiatric comorbidity may be observed across the spectrum of cannabis product use among adolescents, particularly poly-product users.