The purpose of this study is to evaluate the impact of the school-based Sources of Strength program in reducing suicidal behaviors in the population of high school students and determine how the program works (mechanisms of change). Sources of Strength trains diverse high school students as Peer Leaders, who conduct school-wide prevention messaging activities with ongoing adult mentoring designed to increase positive coping norms and practices, help-seeking and increase youth-adult connections. Sources of Strength is expected to enhance school coping practices, increase help-seeking among distressed and suicidal youth, and reduce the number of students in the population who attempt suicide. A total of 40 high schools in primarily rural and micropolitan regions of New York State and North Dakota will participate in this study that uses a randomized wait-listed design.

Investigators will enroll and conduct this trial with 3-4 separate cohorts of high schools over five years, allowing the logistical load to be evenly distributed throughout the study (total 40 schools). Randomization will occur at the school level since Sources of Strength is a school-wide intervention. In each cohort, schools will be enrolled as pairs from the same regions in New York State or North Dakota, for a total of six pairs per cohort. One school from each pair will be randomly assigned to begin training within a few months (Immediate Intervention) or to a wait-list to receiving training approximately 2 years later (Wait List). By pairing schools from the same region and state, before they are randomly assigned to one of the two study conditions, the design reduces the potential for external events (e.g., suicide of a local celebrity) biasing students' behaviors or self-reports within one of the conditions, which could affect investigators' ability to evaluate intervention impact.

The active intervention period in each cohort will span approximately 16 months to test the impact on the school population of Sources of Strength training and messaging steps over two school years, which is the optimal time-period for this intervention. Schools assigned to the Wait List Condition will receive training and begin program implementation in the fall of the third school year, and investigators will provide those schools with training and technical assistance to complete the intervention over 16 months, fully comparable to the early intervention schools.

To assess outcomes of suicide attempts, hypothesized mechanisms of intervention impact (coping norms and practices, connections with adults and peers), and mental health and behavioral risk factors, investigators will conduct a baseline and 3 repeated surveys of the student population in each school using surveys. The investigators have successfully employed this strategy previously to test Sources of Strength in 12 high schools in New York and North Dakota and attained high rates of participation, commensurate to or higher than other studies evaluating screening or other community suicide prevention strategies. Baseline surveys (B) will be administered to all students in schools in both conditions before the intervention begins in any school. The next survey administrations will occur at the end of the first school year (6 months, T1), the beginning of the next school year (12 months, T2), and end of the second school year (18 months, T3). Investigators will provide full training and support for those cohort 3 control schools to complete their intervention. In addition, social network data (close friend nominations, trusted adults named) will be collected across all schools to determine network mediators of intervention effects.

Inclusion Criteria:

• currently enrolled high school students

Exclusion Criteria:

• below 7th grade reading level in English
• parent declines permission