Evaluating a selective prevention program for substance use and comorbid behavioral problems in adolescents with mild to borderline intellectual disabilities: Study protocol of a randomized controlled trial

BACKGROUND: Substance use and abuse is a growing problem among adolescents with mild to borderline intellectual disabilities (ID). Substance use patterns in general population are similar to patterns among non-disabled peers, but substance use has more negative consequences for adolescents with mild to borderline ID, and they are at an increased risk for developing a substance use disorder. Nevertheless, effective and evidence based prevention programs for this groups are lacking. The study described in this protocol tested the effectiveness of a selective intervention aimed at reducing substance use in adolescents with mild to borderline ID and behavioral problems. In the intervention, participants acquire competences to deal with their high-risk personality traits. METHODS: A randomized controlled trial will be conducted among 14–21-year old adolescents with mild to borderline ID and behavioral problems admitted to treatment facilities in the Netherlands. Inclusion criteria are previous substance use and personality risk for substance use. Participants will be individually randomized to the intervention (n = 70) or control (n = 70) groups. The intervention group will be exposed to six individual sessions and five group sessions carried out by two qualified trainers over six-week period. Primary outcomes will be the percentage reduction in substance use (for alcohol: percentage decrease of binge drinking, weekly use and problematic use, for cannabis: the percentage decrease of lifetime cannabis use and weekly use and for hard drug: the percentage decrease of lifetime use). Secondary outcomes will be motives for substance use, intention to use, and internalizing and externalizing behavioral problems. All outcome measures will be assessed after two, six, and twelve months after the intervention. DISCUSSION: This study protocol describes the design of an effectiveness study of a selective prevention program for substance use in adolescents with mild to borderline ID and behavioral problems. We expect a significant reduction in alcohol, cannabis and hard drug use among adolescents in the intervention group compared with the control group. TRIAL REGISTRATION: This trial is registered in the Dutch Trial Register (Cochrane Collaboration) as NTR5037 registered at 15 April 2015.