Preventive intervention effects on developmental progression in drug use: structural equation modeling analyses using...

This study examined the plausibility of the gateway hypothesis to account for drug involvement in a sample of middle school students participating in a drug abuse, prevention trial. Analyses focused on a single prevention approach to exemplify intervention effects on drug progression. Improvements to social competence reduced multiple drug use at 1- and 2-year follow-ups. Specific program effects disrupted drug progression by decreasing alcohol and cigarette use over 1 year and reducing cigarette use over a 2-year period. Controlling for previous drug use, alcohol was integrally involved in the progression to multiple drug use. Subgroup analyses based on distinctions of pretest use/nonuse of alcohol and cigarettes provided partial support for the gateway hypothesis. However, evidence also supported alternate pathways including cigarette use as a starting point for later alcohol and multiple drug use. Findings underscore the utility of targeting more than one gateway substance to prevent escalation of drug involvement and reinforce the importance of social competence enhancement as an effective deterrent to early-stage drug use.