The Preventure Program is the first and only school-based alcohol and drug prevention program that has been shown to prevent onset and growth in alcohol and substance misuse in British and Canadian youth. Unlike universal programs that tend to promote generic coping skills and balance normative attitudes around substance use, this selected personality-targeted approach is based on a psychosocial model and validated by Dr Patricia Conrod and targets four personality-specific motivational pathways to substance misuse: Hopelessness, Anxiety Sensitivity, Impulsivity and Sensation Seeking, each associated with different motives for substance use, drug use profiles and patterns of non-addictive psychopathology.

As a primary goal of the Coventure project, the investigators propose a long-term trial of this intervention strategy to examine how this evidence-based intervention can reduce onset of substance use disorders in young people and related secondary mental health, academic and cognitive outcomes.

As a secondary goal, the investigators propose to use sensitive neuropsychological measures to examine how this evidence-based intervention can positively impact on cognitive development over the course of adolescence, to tease apart some of the mechanisms involved in the causal pathway from early onset substance use to poor cognitive development and long-term addiction outcomes.

This is a cluster randomized design in which 31 high schools across Montreal, Canada will be randomly assigned to receive training and to deliver the program to two cohorts of Grade 7 students or to be trained and assisted in delivering the program to future Grade 7 cohorts. Assessment of participating students will occur annually from September to May until the end of high school year. Students will be assessed on personality, substance use, mental health and cognitive measures.

The program involves delivering specialized coping skills group workshops to students when they are in the 7th or 8th grade. About 45% of students in a given grade will be invited to participate in the workshops.

The workshops will focus on motivating children to understand how their personality style leads to certain emotional and behavioural reactions. They will be guided in learning cognitive behavioural skills on how to channel their strengths towards their long-term goals. Four different workshops will be run, focusing either on managing impulsivity, sensation seeking, anxiety sensitivity or negative thinking.

The students will first be asked to participate in a 45-60 minutes survey asking them about their personality, their strength and weaknesses, their risk-taking behaviour and their learning style.

Then, if their school has been trained to deliver the program, they might be invited to participate in two 90-minute workshops, delivered at school during class time or lunch hour. All children who agree to participate in the study will be invited to complete the same survey in each subsequent academic year for the next four years.

Primary outcomes:

1. Short-term: delayed onset of alcohol and substance use (up to two years post intervention)
2. Long-term: prevention of onset of substance use disorder (at 5th year follow-up).

Secondary intermediate outcomes are neuropsychological functions, for which two hypotheses will be investigated regarding the possible effects of delaying early substance use:

1. Global Effects Hypothesis: substance use and binge drinking will have global harmful effects on cognition and interventions that successfully prevent substance use onset will result in global improvements in cognitive function in participants who received the intervention relative to those randomized to control condition.
2. Critical Developmental Period Hypothesis: the toxic effects of alcohol and drug use are developmentally specific, so effects of interventions will be observed on cognitive processes that are maturing in adolescence, namely, executive functions and reward sensitivity, after controlling for general intelligence quotient (IQ) and memory function following procedure described by Séguin, et al (2004).

Secondary outcomes will be measures of poor mental health and functional cognitive measures such as academic achievement and school drop-out.

Inclusion Criteria:

• Public or private high school
• Must have a Grade 7 cohort of at least 100 youth (up to 200), providing access to 45-90 high risk students per school Selection of high risk youth: Inclusion criteria for students are that they be enrolled in Grade 7 and that they have provided active assent and passive parental consent to participate in the longitudinal survey and randomised trial phases of this study. Participants who score 1 standard deviation above the school mean on one of four subscales of the Substance Use Risk Profile Scale will be selected to participate in the intervention groups, but all students will be followed on outcomes. There are no other exclusion criteria for participants.

Exclusion Criteria:

• Schools cannot be classified as having a majority of their students coded as special needs students, because these schools are smaller and the intervention protocol would have to be tailored for their particular needs

Data will be shared following submission of a formal request.

Data are collected by assessors who are blind to school condition, and the investigators are blind to treatment condition until primary outcomes are analysed. The study will be unblinded at the end of the 5th year of follow-up (post intervention). Individuals receiving targeted interventions are not blind to intervention condition, neither are school administrators and counsellors, but randomization is masked from all other students and staff at the school.