Global, regional, and national burden of five major mental disorders in working-age population, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND: Mental disorders are leading causes of disability worldwide. This study aimed to examine the burden and trends of five major mental disorders-schizophrenia, depressive disorders, bipolar disorder, anxiety disorders, and eating disorders-among working-age population (adults aged 20-64 years) at global, regional, and national levels from 1990 to 2021. METHODS: Data on the number and age-standardized rates (ASRs) of incidence, prevalence, and years lived with disability (YLDs) for the five major mental disorders were extracted from the Global Burden of Disease (GBD) 2021. Data were stratified by sex, age groups (20-24, 25-29, 30-34, 35-39, 40-44, 45-49, 50-54, 55-59, and 60-64), five socio-demographic index (SDI) regions, 21 GBD regions, and 204 countries/territories. A simulation approach sampling from log-normal probability distributions was used to estimate the combined number and rate of five mental disorders. To facilitate comparisons across varying regions and periods, direct standardization was applied for the age group of 20-64. Age-standardized incidence rate (ASIR), age-standardized prevalence rate (ASPR), and age-standardized YLDs rate per 100,000 population were calculated. The trends from 1990 to 2021 were analyzed using the Estimated Annual Percentage Change (EAPC). The numbers were presented with 95% uncertainty intervals, while ASRs and EAPC were presented with 95% confidence intervals (CIs). RESULTS: From 1990 to 2021, the ASIR of total five mental disorders per 100,000 population decreased from 5958.64 (95% CI: 4611.77, 7700.71) in 1990 to 5824.85 (95% CI: 4456.57, 7610.00) in 2019, then increased to 6886.24 (95% CI: 5253.93, 9017.71) in 2021. The EAPC for ASIR was -0.28 (95% CI: -0.37, -0.19) for the period 1990-2019 and 8.73 (95% CI: -0.04, 18.26) for the period 2019-2021. ASPR followed a similar trend, dropping from 11,245.03 (95% CI: 9020.15, 14045.23) per 100,000 population in 1990 to 11,167.93 (95% CI: 8920.87, 14005.12) per 100,000 population in 2019, then rising to 12,749.63 (95% CI: 10146.50, 16042.68) per 100,000 population in 2021, with the EAPC of -0.10 (95% CI: -0.14, -0.06) for the period 1990-2019 and 6.85 (95% CI: 1.70, 12.25) for the period 2019-2021. ASRs of YLDs per 100,000 population moved from 1931.88 (95% CI: 1325.53, 2775.82) in 1990 down to 1922.36 (95% CI: 1313.18, 2772.93) in 2019, and then rose to 2162.31 (95% CI: 1474.36, 3123.61) in 2021. The EAPC for ASR of YLDs was -0.10 (95% CI: -0.14, -0.06) from 1990 to 2019, while for the period 2019-2021, it was 6.06 (95% CI: 0.99, 11.38). Depressive and anxiety disorders dominated among mental disorders, with depressive disorders recording the highest numbers and ASRs. Low SDI regions indicated the highest ASIR, while high SDI regions recorded the highest ASPR and ASR of YLDs for five total mental disorders. Among 204 countries/territories, Greenland had the highest ASIR, ASPR, and ASR of YLDs for five total mental disorders. CONCLUSION: This study underscores a global increase in the burden of five major mental disorders among working-age population from 1990 to 2021, with ASRs rising notably after 2019. It underscores the critical need for tailored interventions that are sensitive to the varied impacts across different sexes, age groups, regions, and specific types of mental disorders, thereby enabling the optimal allocation of medical resources.