Multiple risk factor model predicting cannabis use and use disorders: a longitudinal study.

BACKGROUND

Identification of factors associated with the initiation and continuation of cannabis use is important for any preventive work.

OBJECTIVES

This study aimed to examine the early life course predictors of cannabis use and the development of cannabis use disorder in early adulthood.

METHODS

Data from Mater Hospital and University of Queensland Study of Pregnancy (MUSP), a population-based prospective birth cohort study. Participants were a cohort of 2,493 young adults who completed the life-time version of the Composite International Diagnostic Interview-computerized version (CIDI-Auto) at the 21-year follow-up, and for whom data were available from previous follow-ups. Ever use and age at first use of cannabis was assessed via self-report, and cannabis use disorder was measured based on Diagnostic and Statistical Manual version IV (DSM-IV) diagnostic criteria. Life course predictors were obtained between the child's birth and the 14-year follow-up.

RESULTS

Of 2,493 young adults, 51.4% reported having ever used cannabis, and 21.1% of young adults were classified as having ever had a cannabis use disorder. Child's gender, changes in maternal marital status, maternal smoking, child school performance, childhood sexual abuse, early adolescence smoking and alcohol consumption, and adolescent aggression/delinquency were strongly associated with young adult cannabis use and use disorder. Exposure to multiple risk factors was associated with greater risk of outcomes.

CONCLUSIONS

There are a number of strong predictors of cannabis use identified in this study. They suggest that the social context within which children are reared has a major influence on cannabis use and use disorders.