Impact of Sources of Strength on adolescent suicide deaths across three randomized trials.

Universal interventions are key to reducing youth suicide rates, yet no universal intervention has demonstrated reduction in suicide mortality through an RCT. This study pooled three cluster-RCTs of Sources of Strength (n=78 high schools), a universal social network-informed intervention. In each trial, matched pairs of schools were assigned to immediate intervention or wait-list. Six schools were assigned without a pair due to logistical constraints. During the study period, no suicides occurred in intervention schools vs four in control schools, that is, suicide rates of 0 vs. 20.86/100,000, respectively. Results varied across statistical tests of impact. A state-level exact test pooling all available schools showed fewer suicides in intervention vs. control schools (p=0.047); whereas a stricter test involving only schools with a randomised pair found no difference (p=0.150). Results suggest that identifying mortality-reducing interventions will require commitment to new public-health designs optimised for population-level interventions, including adaptive roll-out trials.

Peer-adult network structure and suicide attempts in 38 high schools: implications for network-informed suicide prevention.

BACKGROUND: Strengthening social integration could prevent suicidal behavior. However, minimal research has examined social integration through relationship network structure. To address this important gap, we tested whether structural characteristics of school networks predict school rates of ideation and attempts. METHODS: In 38 US high schools, 10,291 students nominated close friends and trusted adults to construct social networks. We used mixed-effects logistic regression models to test individual student networks and likelihood of suicidal ideation (SI) and suicide attempts (SA); and linear regression models to estimate associations between school network characteristics and school rates of SI, SA, and SA among all with ideation. RESULTS: Lower peer network integration and cohesion increased likelihood of SI and SA across individual and school-level models. Two factors increased SA: student isolation from adults and suicidal students' popularity and clustering. A multivariable model identified higher SA in schools where youth-adult relationships were concentrated in fewer students (B = 4.95 [1.46, 8.44]) and suicidal students had higher relative popularity versus nonsuicidal peers (B = 0.93 [0.10, 1.77]). Schools had lower SA rates when more students named the same trusted adults named by friends and many students named the same trusted adults. When adjusting for depression, violence victimization and bullying, estimates for adult network characteristics were substantially unchanged whereas some peer effects decreased. CONCLUSIONS: Schoolwide peer and youth-adult relationship patterns influence SA rates beyond individual student connections. Network characteristics associated with suicide attempts map onto three theory-informed domains: social integration versus thwarted relational needs, group cohesion, and suicidal students' social influence. Network interventions addressing these processes, such as maximizing youth-adult connections schoolwide and heightening influence of youth with healthy coping, could create more protective schools. Longitudinal and intervention studies are needed to determine how schools differentiate in network structure and clarify reciprocal dynamics between network characteristics and suicidal behavior.

Diffusion of a Peer-Led Suicide Preventive Intervention Through School-Based Student Peer and Adult Networks.

Background: Peer-led interventions have been applied to prevent various health behavior problems and may be an important complement to individual-level suicide prevention approaches. Sources of Strength trains student "peer leaders" in secondary schools to conduct prevention activities that encourage other students to build healthy social bonds and strengthen help-seeking norms. Prior work examining diffusion of peer-led programs has focused on youths' closeness to peer leaders but minimally on other factors such as connections to adults and suicidal behavior. Methods: We examined implementation and dissemination of Sources of Strength in 20 schools. Over 1 year 533 students were trained as peer leaders and 3,730 9th-12th graders completed baseline surveys assessing friendships and adults at school, and suicidal thoughts/behaviors; and end-of-year surveys reporting intervention exposure: viewed poster/video, attended presentation, direct peer communication, and activity participation. Chi-square tests compared exposure rates by student and network characteristics. Multi-level logistic regression models tested predictors of exposure across individual and school-level characteristics. Results: Exposure to the intervention varied greatly by school and by individual student characteristics and network position. Training more peer leaders increased school-wide exposure for all modalities except presentation (Bs 0.06-0.10, p's < 0.05). In multivariate models, exposure was consistently higher for students closer to peer leaders in the friendship network (ORs 1.13-1.54, p's < 0.05) and students who named more trusted adults (ORs 1.08-1.16, p's < 0.001); and lower for males (ORs 0.56-0.83, p's < 0.05). In multivariate models, training more students as peer leaders predicted exposure to poster-video and direct peer communication in larger schools (OR = 3.34 and 2.87, respectively). Network characteristics influenced exposure similarly for students with suicidal thoughts and behaviors. Discussion: Our findings confirm prior work showing the importance of personal affiliations to peer leaders and natural networks as a medium for diffusion of peer-led prevention efforts. We build on that work by showing independent effects of closeness to adults at school and number of peer leaders trained. There is a need to strategically select peer leaders to maximize closeness to students school-wide, particularly in larger schools. Additional work is required for Sources of Strength to devise messaging strategies to engage males and students isolated from adults at school.