Objectives

The present study focused on the sustainability of the effects of Multisystemic Therapy (MST) on delinquency and recidivism.

Methods

A sample of 256 juveniles with severe and persistent antisocial behavior were randomly assigned to MST (147) and Treatment As Usual (TAU) (109) condition. Pre-test assessment took place before the start of MST/control group treatment. Post-test assessment took place at 6 months after termination of the program. Delinquency (parent and adolescent reported) was assessed 6 months after termination of the treatment. Official judicial data were collected to assess recidivism, with a mean length of follow-up of 3.06 years. ANCOVAs and survival analyses were used to test the effectiveness of MST.

Results

The multi-informant data showed that MST is effective in diminishing delinquent behavior as reported by adolescents and parents, with d’s larger than at post-test assessment immediately after ending of the intervention. The official judicial data, however, suggest that there are no differences between MST and TAU in recidivism. Few and inconsistent moderator effects were found.

Conclusions

According to parent and adolescent reports, the beneficial effects of MST were sustained at the follow-up. This was not supported by official data. These results stress the importance of using multi-informant data on delinquency, as each source of information has its own advantages and disadvantages.