Does the "gateway" sequence increase prediction of cannabis use disorder development beyond deviant socialization? Implications for prevention practice and policy.

BACKGROUND: This study was conducted to test whether non-normative socialization mediates the association between transmissible risk measured in childhood and cannabis use disorder manifested by young adulthood, and whether the sequence of drug use initiation ("gateway", i.e., consuming legal drugs before cannabis, or the reverse) increases accuracy of prediction of cannabis use disorder.

METHODS: Sons of fathers with or without substance use disorders (SUDs) related to illicit drugs were tracked from 10-12 to 22 years of age to model the association between transmissible risk for SUD, socialization (peer deviance), order of drug use initiation ("gateway" or reverse sequence), and development of cannabis use disorder. Path analysis was used to evaluate relationships among the variables.

RESULTS: Non-normative socialization mediates the association between transmissible risk measured during childhood and cannabis use disorder manifest by young adulthood. The sequence of drug use initiation did not contribute additional explanatory information to the model.

CONCLUSIONS: The order of drug use initiation does not play a substantial role in the etiology of cannabis use disorder.