Early interventions in mental health services: a rapid review of systematic review.

Background: Mental health disorders account for a substantial global burden of disease, with many individuals experiencing significant delays in receiving appropriate care. Early intervention has emerged as a key strategy to improve clinical, functional, and economic outcomes across the mental health continuum. Although evidence surrounding early intervention is well established, a broader synthesis of early intervention models across diagnoses, age groups, and service settings has been lacking. Objectives: This Rapid Review sought to map and synthesize systematic review evidence on early intervention mental health services to inform policy, planning, and implementation strategies. Methods: This rapid review of systematic reviews and meta-analyses was conducted to provide a timely synthesis of high-level evidence on early intervention mental health services. Seven electronic databases (MEDLINE, PubMed, Embase, PsycINFO, CINAHL, Cochrane Library, and Scopus) were searched for English-language systematic reviews and meta-analyses published between January 2015 and June 2025. Eligible reviews examined early intervention models for individuals with or at risk of mental health disorders and reported outcomes related to effectiveness, accessibility, cost-effectiveness, patient satisfaction, or system-level performance. Data were synthesized narratively. Results: Eleven systematic reviews and meta-analyses met the inclusion criteria. Early Intervention in Psychosis services consistently reduced hospitalization, treatment discontinuation, and symptom severity while improving social and vocational functioning. Family-focused interventions enhanced caregiver knowledge and wellbeing. Brief crisis intervention models for children and youth reduced emergency department revisits and inpatient admissions. Digital and smartphone-enabled interventions demonstrated feasibility and user engagement, though evidence for sustained clinical benefit remains limited. Economic evaluations showed early psychosis intervention to be cost-effective relative to standard care, but data from low- and middle-income countries were sparse. Key barriers to effective implementation included stigma, fragmented care pathways, and insufficient mental health literacy; facilitators included family involvement, continuity of care, and flexible service delivery. Conclusions: Early intervention models improve outcomes and are often cost-efficient. To maximize impact, health systems should prioritize accessibility, continuity, family engagement, and cultural responsiveness, while expanding evaluation of digital and community-based approaches across diverse settings.