The association of specific traumatic experiences with cannabis initiation and transition to problem use: Differences...

To examine the contribution of trauma exposure to cannabis initiation and transition to first cannabis use disorder (CUD) symptom in African-American (AA) and European-American (EA) emerging adults.

Data are from the Missouri Adolescent Female Twins Study [(N=3787); 14.6% AA; mean age=21.7 (SD 3.8)]. Trauma exposures (e.g. sexual abuse, physical abuse, witnessing another person being killed or injured, experiencing an accident, and experiencing a disaster) were modeled as time-varying predictors of cannabis initiation and transition to CUD symptom using Cox proportional hazards regression. Other substance involvement and psychiatric disorders were considered as time-varying covariates.

Analyses revealed different trauma-related and psychiatric predictors for cannabis use supporting racially distinct etiologic models of cannabis involvement. For AA women, history of witnessing injury/death or experiencing a life-threatening accident was associated with cannabis initiation across the complete emerging adult risk period while sexual abuse predicted cannabis initiation only before 15 years old. For EA women, history of sexual or physical abuse and major depressive disorder (MDD) predicted cannabis initiation and physical abuse and MDD predicted transition from initiation to first CUD symptom. No association was discovered between trauma exposures and transition to first CUD symptom in AA women.

Results reveal trauma exposures as important contributors to cannabis initiation and to a lesser extent transition to CUD symptom, with different trauma types conferring risk for cannabis involvement in AA and EA women. Findings suggest the importance of considering racial/ethnic differences when developing etiologic models of cannabis involvement.