Brief report: Follow-up outcomes of multisystemic therapy for adolescents with an intellectual disability and the relation with parental intellectual disability.

There was no control group, so changes over time cannot be ascribed to MST-ID. Only 40 of 55 parents completed the 6-month interview, 33 completed the 12-month interview and 27 completed the 18-month interview. Families with complete follow-up had more parenting stress at baseline than families with missing follow-up data. Estimated data produced smaller effect sizes and less positive outcomes than original data, and yes/no outcomes could not be statistically tested over time. Only one parent per family was screened for intellectual disability, so another caregiver's disability may have been missed. Adolescents with mild intellectual disability and borderline intellectual functioning were combined, so findings may not apply to each group separately. The sample was small, with 32 parents with intellectual disability and 23 parents without.

Do not conclude that MST-ID caused the reductions. The study had no control group, so outcomes cannot be ascribed to the treatment condition. Only 27 of 55 parents completed the 18-month interview, and estimated-data results were less positive than original data.