Process variables predicting changes in adolescent alcohol consumption and mental health symptoms following personality-targeted interventions

•This study explores change processes following personality-targeted interventions.•Youth feedback accounted for up to 25% of the variance in alcohol use over 1 year.•Youth self-report experiences may represent a proximal measure of program efficacy.•Cognitive-behavioural skills and goal-setting exercises are key intervention features.•Qualitative data can inform on intervention process and subsequent changes.

ObjectiveThis study aims to identify key process variables that are associated with changes in alcohol consumption and mental health symptoms over 12 months following personality-targeted interventions in youth.Method154 high-risk youth (aged 12-13 years) in 7 Montreal high schools were identified using the Substance Use Risk Profile Scale and participated in personality-matched interventions. Preliminary process variables were identified using a combination of psychotherapy process variables and youth-generated (qualitative) feedback immediately post-intervention.ResultsLearning, skill development and a positive group experience were key to positive behavioural change. Youth-generated feedback independently accounted for 12-25% of the variance in the change in alcohol use and mental health symptoms over 12 months. Changes in cognitive distortions and self-esteem accounted for somewhat less of the variance in alcohol use (0-9%), but a moderate-to-large portion of the variance in changes in mental health symptoms (up to 44%).ConclusionsThe study findings highlight candidate process variables relevant to future implementations of this program that might inform change processes relevant to brief interventions with youth more generally. This study suggests that youth experiences can indicate proximal measures of program efficacy, and has implications for the dissemination of this brief intervention program.Clinical Trial registered on www.ClinicalTrials.gov, “Does Delaying Adolescent Substance Use Lead to Improved Cognitive Function and Reduce Risk for Addiction”, study NCT01655615.