Global estimates of service coverage for severe mental disorders: findings from the WHO Mental Health Atlas 2017.

Background: The study estimated service coverage for severe mental disorders (psychosis, bipolar disorder and moderate-severe depression), globally and regionally, using data collected from the Mental Health Atlas 2017.

Methods: Service coverage was defined as the proportion of people with a disorder contacting a mental health service among those estimated to have the disorder during a 12-month period. We drew upon 12-month service utilisation data from the Mental Health Atlas 2017. Expected prevalent cases of individual disorders were estimated using the disorder-specific prevalence rate estimates of the Global Burden of Disease Study 2016 and total population sizes. Methods for assessing the validity of country-reported service utilisation data were developed and applied.

Outcomes: From 177 countries, 50 countries provided reliable service coverage estimates for psychosis, along with 56 countries for bipolar disorder, and 65 countries for depression. The mean service coverage for psychosis was lowest in low- [10.9% (95% confidence interval (CI) 3.3-30.4)] and lower middle-income countries [21.5% (95% CI 11.9-35.7)] and highest in high-income countries [59.5% (95% CI 42.9-74.1)]. Service coverage for bipolar disorder ranged between 3.1% (95% CI 0.8-11.5) and 10.4% (95% CI 6.7-15.8). Mean service coverage for moderate-severe depression ranged between 2.9% (95% CI 1.3-6.3) for low-income countries and 31.1% (95% CI 18.3-47.6) for high-income countries.

Interpretation: The reporting method utilised by the Mental Health Atlas appears to be reliable for psychosis but not for depression. This method of estimating service coverage provides progress in tracking an important indicator for mental health; however, it highlights that considerable work is needed to further develop global mental health information systems.