Effectiveness of Take it Personal!

A controlled pre-post design study on Take it Personal! has demonstrated effectiveness in reducing the frequency and severity of youth use of alcohol, cannabis or other illicit drugs. Take it Personal! is an existing indicated prevention programme for substance use in youth with a mild intellectual disability or borderline intellectual functioning that addresses each participant's high-risk personality traits for substance abuse. The current Take it Personal! programme is further developed and optimized in collaboration with relevant stakeholders. In particular, the investigators aim to integrate personalized daily diary monitoring in the programme so that trainers can monitor client progresses closely and gain insights into change mechanisms, providing starting points for therapeutic efforts in programme sessions. The investigators conduct a series of case studies with a non-concurrent multiple baseline design to evaluate the effectiveness of Take it Personal!. The baseline lengths are randomly determined, and therefore the start of the intervention is staggered across participants.