The goal of this interventional study is to assess the effectiveness of the universal suicide prevention program "Youth Aware of Mental Health" in 3rd-year secondary education students in Galicia.

The main questions it aims to answer are:

• Is the YAM program effective in reducing severe suicidal ideation at 12 months from baseline within the experimental group and compared to the control group?
• Is the YAM program effective in preventing the incidence of new suicidal attempts, 12 months from baseline in the experimental group compared to the control group?

All participants in this study will be asked to:

Complete a survey at baseline and after 12 months, consisting of measures for suicidal ideation and behavior, depressive symptoms, seeking help behaviors, bullying, problematic internet use, and emotional distress.

Only those allocated to the experimental group will be asked to:

Undergo the YAM program, an evidence-based intervention structured into five one-hour class group sessions (45-50 min.), focused on problem-solving by peers. The program consists of interactive presentations, dilemma discussions, role-playing, and reflection, all moderated by a trained YAM instructor.

Twelve months after the intervention, all participants will undergo a re-evaluation using the same protocol. The researchers will compare differences in pre- and post-measures within the experimental and control groups, as well as between both groups, to assess the impact of the YAM intervention on outcomes such as suicidal ideation and attempts.

At the end of the study, those who were allocated to the control group are going to be offered the YAM intervention program.

This multicenter study will be conducted in selected school centers, including both public and private. These centers were identified through two-stage stratified sampling, based on the population distribution in which they are located and their ownership, to be representative of the Galician population in Secondary Education (ESO). Participant randomization does not take place on an individual level. Each cluster's center is identified by a numerical code and assigned to each group (intervention and control group) using a random number generator.

The operationalization of the study will consist of the following phases:

Preparation:

The educational authorities will convene a meeting with the directors or guidance departments of the respective centers. In this meeting, the coordinator of the YAM Team and the Principal Investigator of this study (AGC) will explain what YAM entails, the implementation strategy, and address any questions regarding deployment and logistics. If deemed necessary, an informative session for the parents/guardians of the students will be scheduled. Subsequently, the YAM instructor will contact the school's guidance counselor to arrange the dates for YAM. In control group schools, the same process will be followed, but instead of the YAM intervention, only the pre-test and post-test measures will be collected.

Evaluation:

An initial survey is going to be conducted to collect the measures of all participants. The domains included in this survey will consist of socio-demographic data and measures of suicidal ideation and behavior, depressive symptoms, seeking help behaviors, bullying, problematic internet use, and emotional distress. Following the criteria used in the HBSC survey (Health Behaviour in School-aged Children), this evaluation is going to be conducted individually, in class, and ensuring participant anonymity.

A specialized survey company using CAWI methodology will conduct the surveys, ensuring compliance with the requirements outlined in Regulation (EU) 2016/679 of the European Parliament and of the Council of April 27, 2016, regarding the protection of individuals with regard to the processing of personal data and on the free movement of such data, and with Organic Law 3/2018, of December 5, on the Protection of Personal Data and guarantee of digital rights. The surveys will be anonymized, each center will be identified with a numerical code, and each participating student will be associated with a number. Each student will receive this code at the time of the survey. Neither the research team nor the teacher will be aware of the association between the student's identity and the code, and no list with such an association will be kept, making it impossible to identify the student later. The participation of minors in the clinical trial is regulated by Royal Decree 1090/2015, of December 4, which states that the authorization of parents, guardians, or legal custodians is mandatory. In addition to this authorization, for those over 12 years old, the authorization of the minor is required, and the intervention must be explained to them in appropriate terms.

Intervention:

Once the initial surveys are completed, the YAM intervention will be carried out in the corresponding centers. YAM is structured into 5 one-hour class sessions (45-50 min.).

• Inaugural Session:

Consists of an interactive slide presentation delivered by the YAM instructor, laying the groundwork for the rest of the program. In this first session, the materials to be used are introduced, 6 posters that will be present throughout the program are displayed in the classroom, and students are given a user manual.

• Second session:

The class group is presented with a series of dilemmas outlined on a set of cards to discuss in small groups. These dilemmas are part of the everyday problems of a current school community. The goal is for students to come to their own conclusions when solving problems, rather than the instructor lecturing or solving dilemmas or problem situations.

• Third and fourth sessions:

Contents related to crisis situations, depression, suicidal ideation, and help-seeking behaviors are addressed through role-playing games, allowing the class to integrate their experiences and newly acquired knowledge about mental health through experiential play, reflection, and group discussion. In the role-play sessions, three dilemmas chosen by the class group are addressed. The objective is to discover:

1. how the decisions made make them feel and what the result of those decisions and actions is,

2. become aware of their own feelings and reflect on how to handle stress and crisis situations,

3. listen to others and be able to talk about depression and suicidal thoughts.

   • Closing Session:

A collective summary of the topics is made, and dynamic aspects (relational and emotional) arising during the group experience are addressed.

The YAM intervention is manualized, and all instructors will be recruited from educational and healthcare personnel with clinical experience in adolescents. The instructor group will undergo a 1-week in-person course with the original Swedish team. and a practice period before starting the implementation. YAM instructors will also be specifically trained in the evaluation and management of contingencies related to the appearance of suicidal verbalizations among participants during the implementation of the course. All adverse events will be reported to the school's guidance service and the YAM Team coordinator (AGC), who will jointly decide the steps to be taken in agreement with parents, guardians, or legal custodians following the Action and Prevention Protocol for Suicide Risk in the Health and Educational Environment for Children and Adolescents http://www.edu.xunta.gal/portal/node/38218.

Follow up:

One year after the intervention, the students who participated in the first survey will be re-evaluated using the same system to collect post-measures.

Inclusion Criteria:

• Being a 3rd-year secondary education student at one of the participating school centers
• To be between 13 and 16 years old

Exclusion Criteria:

• Not meeting the inclusion criteria

Note: The YAM is a universal prevention program, therefore, there are no exclusion criteria. Cases with a history of previous suicide attempts (evaluated by the Paykel Scale) in the initial survey will be excluded from the analysis. However, these students will receive the same intervention as the rest of the students. The YAM is not a treatment program and does not aim to demonstrate its efficacy in cases already diagnosed with mental disorders, but it does not exclude individuals with these problems from any potential benefits that participation in the program may have.