Mental health service coverage and gaps among adults in Europe: a systematic review

Ensuring the right to the highest attainable standard of mental healthcare requires a clear understanding of the current state of service coverage and gaps across Europe. Given the wide heterogeneity of health systems and resources, systematically assessing these gaps is crucial in order to identify inequities, inform policy and guide efforts to strengthen care at regional and national levels. In this Series paper, we systematically reviewed 45 studies reporting 198 national or sub-national estimates of adult mental health service coverage and treatment gaps in the World Health Organization (WHO) European Region. Data were scarce for many countries and conditions, heterogeneous in definitions, and rarely longitudinal, limiting comparability and trend analysis. Coverage for psychotic disorders was generally higher, often exceeding 90% in some countries but varied widely. For major depressive disorder, minimally adequate treatment ranged from below 10% in Bulgaria, Tajikistan and Turkmenistan to over 35% in Germany and Czechia. Anxiety disorder coverage ranged from 7% in Bulgaria to 47% in Sweden; most substance use disorder estimates were under 15%, and adult ADHD coverage was typically below 10%, based on outdated data. Trend analyses indicated minimal increases in depression coverage over two decades and mixed patterns for psychosis. Marginalised groups, including refugees, homeless populations and sexual minorities, faced the largest gaps, sometimes exceeding 80%. The lack of standardised, repeated measures hampers tracking of progress toward WHO's 2030 goal of a 50% increase in coverage. We advocate that harmonised monitoring systems, with attention to treatment adequacy and equity, are urgently needed to close persistent mental health care gaps across Europe.