Effectiveness of Multisystemic Therapy for Antisocial and Delinquent Youth with Mild Intellectual Disabilities

Objectives Despite new developments, there still is a lack of evidence-based interventions focusing on Borderline and Mild Intellectual Disabilities (BMID) in children and adolescents. This is especially alarming, because... [ view full abstract ]

Objectives
Despite new developments, there still is a lack of evidence-based interventions focusing on Borderline and Mild Intellectual Disabilities (BMID) in children and adolescents. This is especially alarming, because research has found that youth with BMID are exposed to more risk factors, including social deprivation and mental health problems, than are youth without BMID. Furthermore, youth with BMID have consistently been found to be overrepresented in delinquent youth populations. Based on this knowledge the proven effective intervention Multisystemic Therapy (MST) was adapted to meet the needs of delinquent youth with BMID. MST is an intensive home- and community-based intervention known to reduce recidivism and prevent out-of-home placement of 12-to-18 year olds. In 2012, the adaptation MST-BMID was developed after research had shown that youths with BMID receiving standard MST were placed out of home more often than youths without BMID. MST-BMID targets delinquent youth with an intellectual quotient (IQ) between 50 and 85. The present study aims to determine whether MST-BMID is more effective than standard MST in treating antisocial and delinquent youth with BMID.

Method
A quasi-experimental design was used to compare background characteristics and treatment outcomes of youth with BMID (IQ < 85) treated with standard MST (N = 74) and those treated with MST-BMID (N = 64). It was hypothesised that, for youth with BMID, the treatment outcomes of MST-BMID would be significantly better than the outcomes of standard MST. The primary outcomes were: the youth is living at home (yes/no), the youth is attending school/work for a minimum of 20 hours a week (yes/no), and the youth has had no new arrests during MST (yes/no). The secondary outcomes were: parents show improved parenting skills (yes/no), there is evidence of improved family relations (yes/no), the family has improved their network of informal social support (yes/no), behavioural problems according to the Dutch versions of the Child Behaviour Checklist (CBCL) and Youth Self Report (YSR), parenting skills assessed with the Dutch Opvoedingsbelasting Vragenlijst (OBVL; Burden of Parenting Questionnaire in English), and parental contentment with treatment according to the Dutch Jeugdthermometer GGZ (Thermometer Youth Mental Health Care in English).

Results
Analyses of background characteristics at the start of treatment showed that the youths treated with MST-BMID had significantly lower levels of education than the youths who had received standard MST. These significant lower levels of education were also seen in the parents involved in MST-BMID, which was in contrast with the educational levels of the parents involved in standard MST. Additionally, 58% of the primary caregivers in the MST-BMID group had BMID themselves, as opposed to 22% of the primary caregivers in the standard MST group. No significant differences were found regarding age of the youths, gender of the youths, and ethnicity of the youths and the parents.
Despite the group differences in background characteristics, preliminary results showed that MST-BMID obtained the same results as standard MST on the primary outcomes. The families treated with MST-BMID, however, showed significantly more improved parenting skills, family relations, strengthening of their social networks, and more behavioural changes than the families treated with standard MST. With statistical analyses still in progress, definitive results will be presented during the conference.

Conclusions
The first results suggest that MST-BMID is an effective treatment for youth with BMID. We are currently analysing data on the other outcome measures and, in addition, aim to analyse how differences in background characteristics relate to treatment outcomes.