Background Adolescent suicide is a critical public health concern and one of the leading causes of death among youth globally. In Spain, suicide has been the primary external cause of death since 2008. Rates are especially concerning among adolescents and young adults. Depression and other mental health disorders are major risk factors associated with suicidal thoughts and behaviors in this population.
Schools provide a strategic setting for suicide prevention and mental health promotion, as they offer direct and repeated access to adolescents during a critical stage of emotional development. The involvement of teachers and families is also crucial, as they play a key role in identifying and supporting students at risk.
This study is a two-arm, cluster-randomised controlled trial designed to evaluate the effectiveness of a multifaceted school-based intervention to reduce suicidal ideation and behavior and promote mental health in adolescents aged 12 to 16 years. A total of 38 secondary schools in the Balearic Islands, Spain, will be randomly allocated in a 1:1 ratio to either the intervention or control group, with 2,280 students expected to participate.
Intervention Description
The intervention comprises two components:
1. Student-focused psychoeducational program: Delivered by trained psychologists in four weekly classroom sessions (90 minutes each), this component is based on a comprehensive model of suicide prevention and mental health promotion. The sessions include:
* Mental health literacy and stigma reduction
* Emotional regulation and coping strategies
* Recognition of warning signs and crisis response
* Promotion of help-seeking behavior and strengthening of social support networks Sessions incorporate dynamic group activities to enhance engagement and learning. The program is designed to foster a safe environment for sharing and reflection.
2. Digital co-intervention for parents and teachers: Delivered through a custom-built digital platform, this component includes four knowledge modules with videos, podcasts, and additional educational resources. The content aligns with the student sessions and aims to improve suicide-related knowledge, reduce stigma, increase self-efficacy, and support identification and referral of at-risk students. Access to the platform is monitored through user self-reports and automated engagement tracking.
The control group will receive a minimal intervention in the form of educational posters on mental health and suicide prevention placed in classrooms.
Outcomes and Data Collection Primary and secondary outcomes will be assessed using validated instruments at baseline and six-month follow-up. Primary outcomes include suicidal ideation and behavior. Secondary outcomes include symptoms of depression, psychological well-being, self-harm, substance use, internet addiction, bullying, and help-seeking behaviors. Teachers and parents will report on suicide-related knowledge, self-efficacy, and student referrals.
Process evaluation will be conducted through qualitative interviews with a subsample of students, parents, and teachers to assess the implementation, acceptability, and perceived impact of the intervention.
Data will be analyzed using generalized linear mixed models to account for the clustering of students within schools. Multiple imputation will be used to address missing data. The primary analysis will follow an intention-to-treat approach.
Significance This study addresses a critical gap in the evidence base for suicide prevention programs in Spain. It aims to provide robust data on the effectiveness of a scalable, cost-effective, and digitally enhanced intervention. If successful, the intervention may support wider implementation in schools and contribute to improved mental health outcomes and suicide prevention strategies at the national level.
