The effectiveness of an indicated prevention programme for substance use in individuals with mild intellectual disabilities and borderline intellectual functioning: results of a quasi-experimental study.

Abstract

To assess the effectiveness of Take it personal!, a prevention programme for individuals with mild intellectual disabilities and borderline intellectual functioning (MID-BIF) and substance use (SU). The prevention programme aims to reduce SU (alcohol, cannabis and illicit drugs) among experimental to problematic substance users. A quasi-experimental design with two arms and a 3-month follow-up. Adolescents were recruited from 14 treatment centres in the Netherlands specialized in offering intra- and extramural care for people with MID-BIF and behavioural problems. Data were collected from 66 individuals with MID-BIF assigned either to the intervention condition (n = 34) or to the control condition (n = 32). Take it personal! was designed to target four personality traits: sensation-seeking, impulsive behaviour, anxiety sensitivity and negative thinking. For each of these profiles, interventions were developed that were structurally the same but contained different personality-specific materials, games and exercises. The control group received care as usual. Primary outcomes at 3-month follow-up were frequency of SU, severity of SU and binge drinking. Results showed intervention effects for SU frequency (F_{(1, 50.43)}  = 9.27, P = 0.004) and binge drinking (F_{(1, 48.02)}  = 8.63, P = 0.005), but not for severity of SU (F_{(1, 42.09)}  = 2.20, P = 0.145). A prevention programme to reduce substance use among experimental to problematic users with mild intellectual disabilities and borderline intellectual functioning helped participants to decrease substance use frequency and binge drinking.