"The results of this study suggest that general behavioral deviancy and not specific risk factors accounts for illicit drug use. When illicit drug use occurs first, it is very likely due to the opportunity afforded by the neighborhood environment in context of low parental supervision. The probability and rate of development of a diagnosis of marijuana use disorder and alcohol use disorder were the same whether or not there was conformance with the gateway sequence. Evidence supporting 'causal linkages between stages,' as specified by the gateway hypothesis, was not obtained. Nor were specific risk factors identified that were related to consumption of each drug. Our results indicate that efforts to prevent marijuana use should utilize strategies directed at averting the development of the characteristics prodromal to the manifestation of behavior problems."


Ralph E. Tarter, Ph.D., Michael Vanyukov, Ph.D., Levent Kirisci, Ph.D., Maureen Reynolds, Ph.D., and Duncan B. Clark, M.D., Ph.D. Predictors of Marijuana Use in Adolescents Before and After Licit Drug Use: Examination of the Gateway Hypothesis. American Journal of Psychiatry 2006 163:12, 2134-2140.