Adaptation and feasibility assessment of a school-based Suicide Prevention Intervention for Adolescents (SPREAD Study) in Nigeria: protocol for a cluster randomised controlled feasibility trial.

INTRODUCTION: Adolescent suicide constitutes a critical public health challenge in low-income and middle-income countries (LMICs), where structural deficits in mental health infrastructure compound an already substantial burden. In Nigeria, where suicidal ideation among secondary school students has been documented at a lifetime prevalence of 22.9%, curative clinic-based responses are neither scalable nor sustainable. School-based universal interventions offer a pragmatic upstream alternative. The Youth Aware of Mental Health (YAM) programme has demonstrated robust efficacy in European contexts, reducing incident suicide attempts by approximately 50%; however, its transferability to the West African educational and cultural environment remains untested. This protocol describes a study designed to culturally adapt YAM for Nigerian secondary schools and assess the feasibility of conducting a definitive cluster randomised controlled trial in Lagos State.

METHODS AND ANALYSIS: This study employs a hybrid type 1 effectiveness-implementation design, structured as a two-arm parallel-group cluster randomised feasibility trial across 10 public secondary schools in Lagos State. Approximately 600 adolescents aged 13-17 years will be recruited. Prior to the trial, YAM will be systematically adapted using the Method for Programme Adaptation through Community Engagement framework, producing the YAM-Nigeria curriculum. Schools will be randomised to receive either the culturally adapted YAM-Nigeria programme (five sessions of 45-60 min each delivered by trained external facilitators) or enhanced usual practice (standard health education curriculum supplemented with suicide awareness materials). Primary feasibility outcomes include school recruitment rates (target ≥60%), student consent rates (target ≥70%), retention at the 3-month follow-up (target ≥75%), implementation fidelity (target ≥80% adherence) and acceptability (target ≥70% student satisfaction). Secondary exploratory outcomes include suicidal ideation, depression, mental health literacy, stigma and help-seeking behaviour, measured to estimate the SD and intraclass correlation coefficient required to power a future definitive trial. Progression to a definitive phase III trial will be governed by pre-specified traffic light criteria.

ETHICS AND DISSEMINATION: Ethical approval has been granted by the Lagos State University Teaching Hospital Health Research Ethics Committee (Ref: LREC/06/10/2656) and the Liverpool School of Tropical Medicine Research Ethics Committee (Ref: RGETEM045). A two-stage consent process requiring written parental consent and adolescent assent will be implemented. Findings will be disseminated through open-access peer-reviewed publications, policy briefs for the Lagos State Ministries of Health and Education and plain-language summaries for participating communities.

TRIAL REGISTRATION NUMBER: ISRCTN registry, ISRCTN69846459. Registered on 24 November 2025.