Using integrative data analysis to evaluate sex differences in the effects of multisystemic therapy for justice-involved youth.

The current study examines whether multisystemic therapy (MST), a widely used, developmentally informed, social-ecological intervention for justice-involved youth (JIY), is equally effective for males and females. Justice-involved youth (JIY) have higher rates of substance use relative to youth in the general population. Although interventions like MST often target co-occurring substance use and delinquent behavior, these interventions often neglect female-specific risks and developmental pathways for delinquent behavior and substance use, which raises concern about their appropriateness for female JIY. We use integrative data analysis (IDA) to pool data from three trials of MST to generate sufficient power to detect sex differences in treatment outcomes of self-reported cannabis, alcohol use, and delinquent behavior over the last 90 days. Analyses showed MST was no more effective than services as usual in reducing self-reported substance use and delinquent behavior among JIY through one-year follow-up, nor were treatment outcomes moderated by sex. In the first adequately powered study to compare sex differences in the effects of MST among U.S. JIY, current findings suggest that MST for comorbid delinquent behavior and substance use may need to be improved for both sexes. Continued development and study of effective psychosocial interventions for JIY are needed, and interventions should consider the distinct needs of female JIY.