Background: MST is an intensive home- and community-based intervention for youths with serious antisocial behaviour and other serious clinical problems, which has been effective at reducing out-of-home placements and producing favourable long-term clinical outcomes in the US. The aims of the study were to determine the degree to which these outcomes would be replicated in Norway for youths with serious behaviour problems and to conduct a randomised trial of MST by an independent team of investigators.
Method: Participants were 100 seriously antisocial youths in Norway who were randomly assigned to Multisystemic Therapy (MST) or usual Child Welfare Services (CS) treatment conditions. Data were gathered from youths, parents, and teachers pre- and post-treatment.
Results: MST was more effective than CS at reducing youth internalising and externalising behaviours and out-of-home placements, as well as increasing youth social competence and family satisfaction with treatment.
Discussion: This is the first study of MST outside of the US and one of the first not conducted by the developers of MST. The findings replicate those obtained by MST's developers and demonstrate the generalisability of short-term MST effects beyond the US.