Global burden of early-onset mental disorders in adolescents and young adults: a systematic analysis based on the Global Burden of Disease study 2021

BACKGROUND: Mental disorders represent a major global health challenge. This study aims to quantify the burden of mental disorders among adolescents and young adults (AYAs, aged 15–39) from 1990 to 2021 at global, regional, and national levels, to examine temporal trends and regional disparities, and to assess changes relative to 2019, providing evidence to inform targeted prevention and intervention strategies. METHODS: We analyzed Global Burden of Disease (GBD) data from 1990 to 2021 to assess the incidence, disability-adjusted life years (DALYs), and age-standardized rates of mental disorders (including anxiety disorders, autism spectrum disorders, conduct disorder, eating disorders, schizophrenia, attention−deficit/hyperactivity disorder, bipolar disorder, depressive disorders, idiopathic developmental intellectual disability and other mental disorders) among AYA, stratified by age, gender, sociodemographic index and region. RESULTS: In 1990, the number of incident cases of mental disorders was 120.4 million (94.1 to 153.9 million), increasing to 156.8 million (121.5 to 202.1 million) in 2019, and reaching 195.3 million (149.9 to 253.0 million) in 2021. The age-standardized incidence rate (ASIR) was 5512.73 (4310.87 to 7039.93) in 1990, 5332.9 (4129.93 to 6875.31) in 2019, and 6561.63 (5034.48 to 8502.24) in 2021. The average annual percentage change (AAPC) in ASIR from 1990 to 2019 was −0.12 (−0.13 to −0.1), while from 2019 to 2021, the AAPC sharply increased to 12.15 (7.91 to 15.18). Globally, depressive disorders accounted for the highest number of incident mental disorder cases, while depressive disorders and anxiety disorders were the leading contributors to DALYs. CONCLUSIONS: Since 2019, the incidence of mental disorders among AYAs has risen markedly, with anxiety and depressive disorders accounting for the largest share of the burden. These findings highlight the urgent need for targeted, evidence-based public health interventions and proactive mental health strategies to address emerging challenges and reduce the long-term burden on this vulnerable population.