Background Suicide is one of the leading causes of death among adolescents. Suicidal thoughts and behaviors are significant risk factors for suicide, whilst depressive symptoms are significant risk factors for suicidal thoughts and behaviors. Multimodal school-based interventions that address these risk factors are considered the appropriate approach to suicide prevention.

Method 1,593 adolescents (aged 11-15 years) from 15 high schools in the Netherlands took part in the study, which was designed as a pragmatic cluster-randomized trial. The experimental condition consisted of (1) screening for depressive symptoms and suicidal thoughts and behaviors, followed by referral of those who scored positive; (2) gatekeeper training for school mentors; (3) a serious game to reduce stigma, promote health literacy and improve help seeking behavior; and (4) eight CBT-based sessions for adolescents with elevated depressive symptoms. The control group consisted of screening and the gatekeeper training. Both suicidal thoughts and behaviors and depressive symptoms were assessed at baseline, after 6 months and after 12-months follow-up.

Results Multilevel mixed-model analysis revealed that, over the entire 12-month follow-up period, both suicidal thoughts and behaviors and depressive symptoms increased significantly in the experimental group, but not in the control group. No clinically relevant change was observed in either group.

Conclusions The multimodal stepped-prevention program tested in the present study did not lead to a reduction in suicidal thoughts and behaviors or depressive symptoms. However, it is likely that the adverse impact of COVID-19-related school closures overwhelmed the program’s effectiveness. Furthermore, few high-risk adolescents participated in the CBT-based sessions.

What is known?

School-based prevention programs aim to reduce suicidal thoughts, behaviors, and depressive symptoms among adolescents.

Multi-modal interventions are increasingly promoted, but evidence of their effectiveness is limited under real-world conditions.

What is new?

The multimodal stepped STORM program did not reduce STBs or depressive symptoms at 12-month follow-up; a small group-level increase was observed in the experimental group.

Participation in the indicated CBT-based module was low, revealing critical implementation gaps school programs.

What is significant for clinical practice?

School-based programs should prioritize early identification with active referral, gatekeeper training.

Active referral to a brief CBT-based intervention for high-risk students need to be implemented in close collaboration with both students and teachers to better assure its uptake

Trimbos Institute, Utrecht, has the exploitation rights of the Moving Stories intervention. Trimbos Institute is a not-for-profit WHO Collaborative Centre with the goals to disseminate best and evidence-based practices. The STORM programme is owned by GGZ Oost Brabant, The Netherlands. RE, FS, and MG were at the time of the study employees at Trimbos Institute. SR and DC are employees at GGZ Oost Brabant and are also involved in the national scale-up of STORM in the Netherlands. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

NTR5725

https://doi.org/10.1186/s12888-018-1710-2

Funding for this study was provided by the municipalities of Asten, Deurne, Geldrop-Mierlo, Gemert-Bakel, Helmond, Laarbeek and Someren, The Netherlands. Moving Stories was funded by 'Het Stimuleringsfonds', and OVK was funded by ZonMw. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. GGZ Oost Brabant and the Trimbos Institute provided program materials.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study was approved by the medical ethics committee CMO Regio Arnhem-Nijmegen of the Netherlands (NL61559.091.17) and registered in the Dutch Trial Register for RCT's (NTR5725).

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

Filip Smit is retired from the Trimbos Institute (Netherlands Institute of Mental Health and Addiction), Utrecht, The Netherlands, and Amsterdam University Medical Centers (location VUmc), Amsterdam Public Health research institute, Amsterdam, The Netherlands.

The data that support the findings of this study are not publicly available due to ethical and privacy restrictions. The first author (MG), who conducted the analyses during the study period, had access to the raw data at that time. Access to the data is currently restricted and is held by GGZ Oost Brabant. Requests for access may be directed to GGZ Oost Brabant and are subject to approval by the relevant data governance and ethics committees.