A cluster randomized controlled trial (RCT) of a program based on information and communication technologies (ICT) will be conducted to prevent suicide and strengthen mental health among secondary school students in Chile. The program utilizes a web-based platform and a mobile application to cultivate a virtual community to promote mental health protective factors, such as self-esteem and self-expression, and reduce suicide risk. It is based on the principles of peer-support and inclusivity, and it has been inspired by previous studies in Europe and the US. The trial will take place in six public secondary schools in two cities of Chile: Santiago and Rancagua. Schools will be randomly assigned to either intervention or control conditions. Assessment will be conducted at baseline, 3-month (post intervention), and at 5-months (2 month follow-up).

There is increasing concern regarding adolescent suicide in Latin America. Recent mental health policies foster the development and implementation of preventive interventions for suicide. Such initiatives, however, have been scarcely developed, even in countries with solid mental health services, such as Chile. The use of information and communication technologies (ICT) might contribute to create accessible, engaging, and innovative platforms to promote well-being and support for adolescents with mental health needs and suicide risk. Promising evidence from high-income countries has already shown the potential benefits of ICT-based programs but further research is needed, especially in settings with restrained resources. Providing local evidence is crucial for persuading policy makers and other stakeholders, and it will prove crucial in order to widely disseminate and scale up the program, if it is found to be effective.

A cluster randomized controlled trial (RCT) to evaluate an ICT-based program will be conducted to prevent suicide and enhance mental health among adolescents in Chile. Four-hundred high-school students will be recruited from 6 public schools in two regions of Chile. Study procedures will be as follows: 1) design of the intervention model and creation of prototype; 2) selection and randomization of the participating schools; 3) implementation of the 3-month intervention and evaluation at baseline, post-intervention period, and a 2-month follow-up.

The ICT-based program utilizes a web-based platform and a mobile application to cultivate a virtual community to promote mental health protective factors, such as self-esteem and self-expression, and prevent adolescent suicide. To overcome the frequent barriers to help seeking, the program will provide rapid direct access to quality, evidence-based information and real-time assistance from a mental health professional; encourage habits that improve emotional and physical health; facilitate self-monitoring of mental health and personal progress; and promote social integration and participation in community-based activities. The program is based on the principles of peer support and inclusivity, and as such, its name is "Project Clan," in reference to a diverse group of individuals who come together for a common purpose in a welcoming environment. The privacy and anonymity of each "Clan member" will be respected, so that they feel free to openly express themselves and resolve questions about possibly taboo topics related to mental health and suicide. Project Clan includes both informational and interactive features, ranging from traditional suicide prevention strategies (e.g., a chat with a psychologist, emergency phone hotline, and tips) that seek to reduce barriers to access quality, useful, and evidence-based information and rapid professional assistance; to components designed to increase interactions between participants and promote a sense of belonging and connection with the other Clan members.

Suicidal ideation is the primary outcome in this study. Secondary outcomes include negative psychological outcomes (e.g., stigma, depression, anxiety) as well as a number of protective psychological and social factors. Indicators regarding the study implementation process will be also gathered. Pertinent study documents (e.g., research protocol, instruments, informed consent, and informed assent forms) were approved by the Ethics Committee for Human Subjects Research of the Faculty of Medicine, Universidad de Chile.

Inclusion Criteria:

- Students who attend participating public high schools in two cities (Santiago and Rancagua) of Chile

Exclusion Criteria:

• Students having visual or physical impairments that are incompatible with the intervention model
• Student having a prior diagnosis of a mental disorder.

Given our commitment to the relevancy of this study, we agree to:

1. Register this study at ClinicalTrials.gov. This record will be updated at least every 12 months, as required.
2. Report aggregate results no later than one year after the clinical trial completion date, in a publication.

Furthermore, the University of Chile (UCH) has an internal policy to ensure that clinical trials comply with University and sponsor policy and regulatory standards.