Because these problem behaviors appear to be strongly related, to demonstrate overlap in their developmental course and to share many of the same ecological predictors, particularly those related to parent–child relationships and peer behavior, Capaldi et al. (2002) suggested that family-based prevention programs targeting antisocial behavior in childhood may also show effects on other risk behaviors, such as HRSB. The first goal of our study, then, was to test whether one such intervention, the Family Check-Up (FCU), a family-based prevention program originally designed to disrupt growth in adolescent antisocial behavior and substance use, would also reduce rates of HRSB in a community sample of young adults. A second goal was to examine potential mechanisms underlying a possible intervention effect. Our research helps address a critical need in intervention research: despite increasing numbers of longitudinal randomized prevention trials demonstrating the efficacy of prevention programs for various problem behaviors, there is a dearth of research on the mechanisms that account for program effects (Liddle 2004; Sandler et al. 2011). Finally, our third goal was to determine whether gender and race (i.e., European American vs. African American) moderate these effects, given gender and racial differences in mean levels and etiology of HRSB (Doljanac and Zimmerman 1998; Huebner and Howell 2003; Rodgers 1999).