Abstract
Adolescent mental health difficulties remain a significant educational and public health concern, particularly in contexts where specialist services are limited or unevenly accessible. Schools are frequently positioned as practical sites for mental health promotion, prevention and early intervention because they offer routine access to adolescents and can embed support within existing educational structures. This systematic review synthesised ten peer-reviewed studies on school-based mental health interventions for secondary-school-aged students. Guided by PRISMA 2020 reporting principles, searches were conducted across Google Scholar, PubMed and ERIC, supported by forward citation searching. Data were extracted on study context, intervention type, target population, outcomes and limitations, and included studies were appraised using CASP-informed quality criteria. The review found that school-based interventions generally report positive effects on adolescent mental health and wellbeing, including reductions in anxiety, stress and depressive symptoms and improvements in mental health literacy, coping self-efficacy and resilience-related outcomes. However, the strength and durability of effects varied across intervention types, outcome measures and implementation contexts. The synthesis indicates that effectiveness is not a property of intervention content alone; it is shaped by theoretical alignment, implementation quality, teacher capacity, cultural fit, programme duration and available referral pathways. The review concludes that school-based mental health interventions are promising but should not be treated as universally effective without attention to context, fidelity and evaluation design. The findings are relevant for schools and policymakers in low- and middle-income countries, including Guyana, where school-based approaches may expand access to early mental health support while strengthening links between education and public health systems.