Opening the "Black Box": family check-up intervention effects on self-regulation that prevents growth in problem behavior and substance use.

Family-school interventions are a well-established method for preventing and remediating behavior problems in at-risk youth, yet the mechanisms of change underlying their effectiveness are often overlooked or poorly understood. The Family Check-Up (FCU), a school-based, family-centered intervention, has been consistently associated with reductions in youth antisocial behavior, deviant peer group affiliation, and substance use. The purpose of this study was to explore proximal changes in student-level behavior that accounts for links between implementation of the FCU and changes in youth problem behavior. Data were drawn from a randomized controlled trial study of the efficacy of the FCU among 593 ethnically diverse middle school students followed longitudinally from 6th through 8th grades. Latent growth curve analyses revealed that random assignment to the FCU intervention condition was related to increased mean levels of students' self-regulation from 6th to 7th grades, which in turn reduced the risk for growth in antisocial behavior, involvement with deviant peers, and alcohol, tobacco, and marijuana use through the 8th grade. Overall, these findings highlight the robust implications of self-regulation as a proximal target for family-centered interventions.