Long-term prevention of criminality in siblings of serious and violent juvenile offenders: a 25-year follow-up to a randomized clinical trial of multisystemic therapy.

OBJECTIVE Family-based treatment models that have shown effectiveness with juvenile offenders may also lead to reduced criminality in siblings of those offenders. However, the lasting effects of such treatments on siblings have not been evaluated. In the present study, the authors examined criminal outcomes for siblings of serious and violent juvenile offenders who had participated on average 25.0 years earlier in a clinical trial of multisystemic therapy (MST; Borduin et al., 1995). METHOD Participants were 129 closest-in-age siblings of individuals who were originally randomized to MST or individual therapy (IT) during adolescence. Arrest and incarceration data were obtained in middle adulthood when siblings were on average 38.4 years old. RESULTS Intent-to-treat analyses showed that arrest rates were significantly lower for siblings in the MST condition than in the IT condition (43.3% vs. 72.0%, respectively). In addition, siblings in the IT condition were about 3 times as likely to be convicted of a felony and more than twice as likely to be sentenced to incarceration and probation. CONCLUSION The present study represents the longest follow-up to date of sibling participants in an MST clinical trial and demonstrates that the positive impact of an evidence-based treatment for serious and violent juvenile offenders can extend to other family members. Implications of the authors' findings for policymakers and service providers are discussed.