Implementation of Digital and Analog School-Based Mental Health Programs in Europe Since COVID-19: A Mixed Methods Systematic Review Protocol (Preprint)

BACKGROUND Over the past decade, Europe has expanded school-based mental health prevention programs, yet the prevalence of mental disorders among children and adolescents remains high and has risen further since the COVID-19 pandemic. Digital interventions have proliferated, yet implementation gaps persist, limiting their impact. OBJECTIVE To synthesize quantitative, qualitative, and mixed-methods evidence on the facilitators and barriers to implementing digital and analog universal school-based mental health promotion programs for children and adolescents (ages 5–19) in European primary and secondary schools, and to examine how implementation quality is assessed and the role of the digital environment. METHODS A three-step search will be conducted across the interfaces PubMed, EBSCO, Clarivate Analytics, PubPsych, Fachportal Pädagogik, Google Scholar, relevant preprint servers, and the reference lists of all included sources of evidence. A first systematic search was completed in January 2026. Titles/abstracts and full texts will be screened independently by two reviewers, with disagreements resolved through discussion or a third reviewer. Methodological quality will be appraised by assessing the trustworthiness, relevance, and results of published papers. Data will be extracted using standardized JBI forms and analyzed separately into quantitative (descriptive statistics, possible meta-analysis) and qualitative (meta-aggregation) components, followed by a convergent, segregated synthesis to integrate findings. No deviations from the JBI mixed-methods systematic review methodology are anticipated. RESULTS A comprehensive PubMed search was conducted on January 6, 2026, and 614 records were retrieved after applying filters. Results are expected to be published by December 2026. CONCLUSIONS By integrating quantitative and qualitative findings, this review will identify the key facilitators and barriers influencing the real‑world uptake of digital and analog school‑based mental‑health programs across Europe. Mapping these determinants onto implementation frameworks such as CFIR and RE‑AIM and linking them to program outcomes will yield actionable recommendations that can close the implementation gap, bolster sustainability, and improve mental‑health outcomes for children and adolescents in the post‑COVID era.