Global statistics of attention-deficit/hyperactivity disorder, autism spectrum disorder, and conduct disorder among school-age children from 1990-2021, with forecasts to 2040

Background: Mental disorders among school-age children represent a significant global health issue and substantially contribute to the global disease burden. This study aims to examine the patterns and trends of attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and conduct disorder (CD), which are commonly observed in school-age children, from 1990 to 2021, offering valuable insights for health policy formulation, medical resource allocation, and optimization of patient management strategies. Methods: We analyzed data from the Global Burden of Disease (GBD) 2021 study for 21 regions and 204 countries, focusing on prevalence, disability-adjusted life years (DALYs), gender, and different time periods to gain a deeper understanding of the health burden. We assessed correlations with the Socio-demographic Index (SDI) and employed autoregressive integrated moving average modeling to forecast developments up to 2040, enabling us to better comprehend the burden and trends of these mental disorders. Results: In 2021, the prevalence rates of ADHD, ASD, and CD per 100,000 population among children aged 5-14 years were 2374.8, 847.13, and 2146.48, respectively; DALYs rates were 29.17, 162.85, and 262.53, respectively. Compared to 1990, prevalence and DALYs rates exhibited changes of -0.06, 0.03, and 0.04, respectively. Australia, Japan, and the United Kingdom exhibited particularly notable burdens, with the United Kingdom continuing to show rapid growth in ASD, while ADHD and CD increased rapidly in China and India, respectively. Gender and age analyses revealed a higher burden among males. Regions with high SDI displayed higher epidemiological indicators. For the 2040 forecast, the indicators for ADHD in terms of prevalence and DALYs are projected to be 3796.65 and 44.33 for males, and 1343.18 and 16.23 for females. For ASD, they are projected to be 1103.04 and 215.23 for males, and 552.01 and 106.40 for females. For CD, they are projected to be 2650.69 and 325.64 for males, and 1593.57 and 200.41 for females. Conclusion: This study underscores the complex epidemiological landscape of ADHD, ASD, and CD, revealing variations in burden across gender and geographical regions. It emphasizes the urgent need for healthcare professionals and policymakers to devise innovative prevention and healthcare strategies based on the current and evolving burden of these mental disorders, with the aim of alleviating the global disease burden.