family adversity. The large sample size and study design made it possible to go beyond the variable-centered linear predictions provided by prior longitudinal studies, and to explore variations in individual risk profiles using person-oriented analyses. In addition, the present study offered the opportunity to evaluate the impact of the Fast Track prevention program on early sexual activity, to determine whether a program effective at reducing early aggression and improving the grade school social and academic adjustment of children with early-starting conduct problems might also confer benefits in terms of reducing sexual risk. First, we applied a person-oriented approach (LCA) to better understand the patterns of co-occurring precocious tobacco use, alcohol/drug use, and risky sexual activity in this sample of vulnerable children over sampled for early-starting conduct problems. Second, we explored early childhood behaviors (e.g., externalizing behaviors, attention problems, academic difficulties) and family features (low SES, low parental warmth) as predictors of the development of tri-morbid problem profiles and risky sexual outcomes. We also examined associations between more proximal risks evident in late childhood and preadolescence (e.g., pubertal timing, depressed mood, deviant peer affiliation, and school adjustment) and profiles of tri-morbid risk. Finally, we tested for intervention effects on risky sexual
