Brief school‐based interventions and behavioural outcomes for substance‐using adolescents

Background Adolescent substance use is a major problem in and of itself, and because it acts as a risk factor for other problem behaviours. As substance use during adolescence can lead to adverse and often long‐term health and social consequences, it is important to intervene early in order to prevent progression to more severe problems. Brief interventions have been shown to reduce problematic substance use among adolescents and are especially useful for individuals who have moderately risky patterns of substance use. Such interventions can be conducted in school settings. This review set out to evaluate the effectiveness of brief school‐based interventions for adolescent substance use. Objectives To evaluate the effectiveness of brief school‐based interventions in reducing substance use and other behavioural outcomes among adolescents compared to another intervention or assessment‐only conditions. Search methods We conducted the original literature search in March 2013 and performed the search update to February 2015. For both review stages (original and update), we searched 10 electronic databases and six websites on evidence‐based interventions, and the reference lists of included studies and reviews, from 1966 to February 2015. We also contacted authors and organisations to identify any additional studies. Selection criteria We included randomised controlled trials that evaluated the effects of brief school‐based interventions for substance‐using adolescents. The primary outcomes were reduction or cessation of substance use. The secondary outcomes were engagement in criminal activity and engagement in delinquent or problem behaviours related to substance use. Data collection and analysis We used the standard methodological procedures outlined by The Cochrane Collaboration, including the GRADE approach for evaluating the quality of evidence. Main results We included six trials with 1176 adolescents that measured outcomes at different follow‐up periods in this review. Three studies with 732 adolescents compared brief interventions (Bls) with information provision only, and three studies with 444 adolescents compared Bls with assessment only. Reasons for downgrading the quality of evidence included risk of bias of the included studies, imprecision, and inconsistency. For outcomes that concern substance abuse, the retrieved studies only assessed alcohol and cannabis. We generally found moderate‐quality evidence that, compared to information provision only