Global Inequalities in Access to Evidence-Based Mental Health Care: A Systematic Review of Service Utilization and Health System Performance

Abstract

Mental health disorders are a leading cause of disability worldwide, yet access to evidence-based mental health care remains highly unequal across and within countries. Understanding disparities in access, utilization, and quality is critical for advancing universal health coverage. A systematic review was conducted in line with the PRISMA 2020 guideline. We searched databases such as PubMed, PsycINFO, Web of Science, and grey literature for studies published from January 2010 to March 2026. Data were synthesized using a narrative approach, and methodological quality was assessed using the JBI Critical Appraisal Checklists and the Newcastle-Ottawa Scale (NOS). The database search yielded 3,266 studies. Following study screening and selection, 30 studies were included in this review, and covered multiple countries, including those from high-income and low- and middle-income countries. Globally, treatment coverage was low, with high-income countries having significantly higher coverage than low- and middle-income countries. Inequities were substantial within countries, with low-income individuals, rural residents, and minorities being disproportionately affected. Treatment coverage was below one-third of those in need across most settings, with dropout rates ranging from 20–60% in the first three months. There were notable quality issues, including high dropout rates, long wait times, and inconsistent adherence to evidence-based care. The results suggest that the global treatment gap is not merely a service delivery gap, but also a systemic problem, including failure to deliver services efficiently, in continuity, and quality. The persistent disparities among socioeconomic and geographic groups reveal the effect of larger structural determinants. To decrease mental health inequity, it is necessary to enhance health system capacity, strengthen the workforce, enhance integration into primary care, and incorporate equity-based approaches that can guarantee access and high-quality care.