Barriers and facilitators for the implementation of preventative mental health interventions among secondary schools in high-income countries: A systematic review’

Background. Recent societal crises have negatively impacted the mental health of many children and adolescents, prompting widespread calls for increased efforts to promote mental health and prevent the onset of mental disorders in this age group. Schools as key environments for young people present a valuable opportunity to implement low-threshold mental health interventions that can promote mental health. However, school-based interventions are often not maintained in the long-term, primarily due to various implementation challenges. This systematic review aims to identify barriers and facilitators affecting the implementation of school-based interventions for mental health promotion and mental disorder prevention in secondary schools in high-income countries.Methods. A comprehensive search was conducted across seven databases (incl. APA PsycNet, Embase, CINAHL, Scopus, Web of Science), to identify qualitative or mixed-methods studies that examined the implementation of preventative school-based mental health interventions amongst regular secondary schools in high-income countries. After screening and data extraction, implementation determinants were synthesized using the Consolidated Framework for Implementation Research. Study quality was assessed using modified checklists of the Critical Appraisal Skills Programme.Results. Our search yielded 26 eligible studies, with sample sizes ranging from 5 to 8,630 pupils. A total of 336 distinct implementation factors were identified, with barriers (N=207; 61.6%) outweighing facilitators (N=129; 38.4%). The most common barriers included scheduling conflicts, a lack of priority for mental health interventions, and logistical challenges within the school environment. Key facilitators included leadership support, age-appropriate intervention components, and ongoing staff engagement.Conclusions. To ensure long-term success of preventative school-based mental health interventions it is critical to integrate programs into the school environment by aligning them with academic priorities and addressing pre-existing resource limitations. Future research should focus on adapting interventions to better fit school environments, and on fostering strong leadership and community support to overcome implementation barriers at the team and community level. Addressing multidimensional implementation factors and exploring their complex interaction will be essential for developing and implementing effective and sustainable interventions that can have a long-lasting impact on adolescents’ mental health.Registration. Prospective preregistration at PROSPERO: CRD42023493299.