Skill vs. Disposition: Examining Paths of InterventionEffects in an Alcohol and Drug Use Prevention TrialTargeting U.S. Adolescents

The goal of this study was to evaluate a mediation model of two approaches todeterring the onset of alcohol, cigarette, and marijuana among middle school ado-lescents. Students completed surveys that included yes/no self-reports about theirpast 30-day and lifetime alcohol, cigarettes, and marijuana use. Surveys assesseddispositions: perceptions that drug use would interfere with desired lifestyles, per-ceptions about drug use prevalence and acceptability, and drug use intentions. Sur-veys also assessed skills: students’ ability to achieve goals, make decisions, andrefuse drug use offers. Classrooms were assigned by convenience to one of threeconditions. In the control condition, students (N = 394) received no prescribed in-tervention. Core condition students (N = 101) received instruction in All Stars Core,which targeted changing students’ dispositions. Students in the combined Core andPlus condition (N = 135) received instruction in both All Stars Core and in AllStars Plus, which also targeted improving students’ skills. Analysis revealed that theprograms achieved reductions in the onset of drug use through maintaining thesestudents’ dispositions. In contrast, control students’ dispositions eroded over time,increasing their risk for drug use. The Plus intervention that targeted skills, failed tohave a sufficiently large impact to allow analysis to validate skills as a statisticallysignificant mediator of drug use outcomes. These results speak to the conclusionthat, for prevention programs to succeed at deterring the onset of alcohol and druguse, interventions need to maintain or improve students’ dispositions. This includesimproving lifestyle incongruence, reducing perceptions that drug use is commonand acceptable, and by increasing commitments to avoid drugs. Interventions thatfocus on building skills are less likely to achieve preventive effects.