Randomized trial of a broad preventive intervention for Mexican American adolescents.

Objective: This randomized trial of a family-focused preventive intervention for Mexican American (MA) adolescents evaluated intervention effects on adolescent substance use, internalizing and externalizing symptoms, and school discipline and grade records in 8th grade, 1 year after completion of the intervention. The study also examined hypothesized mediators and moderators of intervention effects.

Method: Stratified by language of program delivery (English vs. Spanish), the trial included a sample of 516 MA adolescents (50.8% female; M = 12.3 years, SD = 0.54) and at least one caregiver that were randomized to receive a low-dosage control group workshop or the 9-week group intervention that included parenting, adolescent coping, and conjoint family sessions.

Results: Positive program effects were found on all 5 outcomes at 1-year posttest but varied depending on whether adolescents, parents, or teachers reported on the outcome. Intervention effects were mediated by posttest changes in effective parenting, adolescent coping efficacy, adolescent school engagement, and family cohesion. The majority of intervention effects were moderated by language, with a larger number of significant effects for families who participated in Spanish. Intervention effects also were moderated by baseline levels of mediators and outcomes, with the majority showing stronger effects for families with poorer functioning at baseline.

Conclusion: Findings not only support the efficacy of the intervention to decrease multiple problem outcomes for MA adolescents but also demonstrate differential effects for parents and adolescents receiving the intervention in Spanish vs. English, and depending on their baseline levels of functioning.