Mental health problems affect 10-20% of children and adolescents worldwide, with half of affected youth experiencing problems by the age of 14. Despite the early onset of mental health problems, evidence-based prevention and early intervention programs remain scarce. If left untreated, early-onset mental health problems can progress to become severe or chronic conditions, and incur significant medical and societal costs.

The current project proposes an integrated screening and intervention model that was developed involving active youth, family and community engagement. This project, known as Inter-Venture, focuses on reducing barriers to youth mental health care and promoting early screening and intervention by fostering collaboration between school and community-based services providers. The Inter-Venture project is being conducted in the Montreal area (Canada), and consists of three intervention modalities. Namely, 1) systematic school-based screening and personality-targeted interventions for students most at risk of mental health problems and substance misuse (the Preventure program); 2) a parent program designed to strengthen parenting skills and to improve the management of child behavior problems (Cope/EQUIPE program); 3) integrated services provided by a multidisciplinary team of professionals (referred to as Inter-Action) for youth with significant symptoms of mental health problems, substance misuse and/or psychosocial difficulties. The intervention model involves knowledge transfer to boost capacity-building and improve the provision and sustainability of evidence-based interventions in community settings.

The primary goal of the Inter-Venture trial is to assess the potential effect of the school-based targeted interventions and collaborative care in the prevention, early detection and reduction of mental health problems, substance misuse and psychosocial difficulties among young people. The secondary goal is to assess the effect of interventions on school performance and whether the interventions can protect cognitive functions that may be negatively affected by early-onset substance use and mental health problems, and promote cognitive development through the prevention of these difficulties.

The Inter-Venture Trial is a cluster-randomised controlled trial of three intervention modalities developed involving active youth, family and community engagement in the Montreal area: (i) Systematic school-based screening and early personality-targeted interventions for students most at risk of mental health problems and substance misuse (Preventure program); (ii) Community-based parent training program and (iii) Timely and integrated services provided by a multidisciplinary team of professionals (Inter-Action).

The trial will assess the potential effects of some of the components of the intervention model in 45 secondary schools that will be randomly assigned to two intervention conditions (receiving Inter-Action services and the parent training program in addition to Preventure or receiving the Preventure program and the parent training program) and a control arm that will receive treatment as usual. Schools will be matched on their baseline socio-economic status. Approximately 4000 students in participating schools will be invited to complete annual assessments for 5 consecutive years from grade 7 to grade 11.

Based on their scores on the Substance Use Risk Profile Scale, at-risk students will be identified and invited to participate in the Preventure program in the first year of the trial. Parents of grade 7 students reporting discord at home on the Alabama parenting questionnaire will be invited to participate to the parent program. Participating students with clinically significant internalizing and externalizing problems will be invited to receive Inter-Action services. Internalizing and externalizing problems will be assessed using self-report measures such as the Patient Health Questionnaire for Adolescents, the Strengths and Difficulties Questionnaire, the screening tool for the detection of alcohol and drug problems in adolescents (DEP-ADO) and the development and well-being assessment (DAWBA).

Primary outcomes will be the likelihood of reporting a significant level of mental health problems, behavioral problems, substance misuse and poor quality of life among participating youth.

Secondary outcomes will include the severity of the symptoms of mental health and substance use problems, school performance, time to received treatment, time in treatment, quality of care, cognitive functioning and other psychosocial outcomes.

Inclusion Criteria:

School inclusion criteria :

- Public or private schools offering regular courses from grade 7 to grade 11.

Student inclusion criteria:

• Being in grade 7 at baseline
• Students' assent to participate
• Parental passive or active consent for students' participation

Parent inclusion criteria

• Being a parent of grade 7 students in a school participating in the parent training program
• Active consent to participate in the study

Exclusion Criteria:

• Schools where the majority of students are coded as special needs students will not be included since the interventions are not adapted to their specific needs