The Co-Venture Trial: A Cluster Randomized Trial of Personality-targeted Interventions on Adolescent Substance Use and Cognitive 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:

• Short-term: delayed onset of alcohol and substance use (up to two years post intervention)
• 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:

• 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.
• 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