The article titled “The global epidemiology and health burden of the autism spectrum: findings from the Global Burden of Disease Study 2021” published in The Lancet Psychiatry (2025), provides the most comprehensive and methodologically revised assessment to date of autism spectrum disorder (ASD) on a global scale. Using updated statistical modeling and robust epidemiological data, this study presents crucial findings for policymakers, researchers, and health service planners.
One of the study’s most striking results is the estimation that approximately 61.8 million people, or 1 in every 127 individuals globally, were on the autism spectrum in 2021. This corresponds to a global age-standardised prevalence of 788.3 per 100,000 people. The prevalence was notably higher in males (1064.7 per 100,000) than in females (508.1 per 100,000), though the revised estimation methods resulted in a lower male-to-female ratio than in previous studies, likely correcting for diagnostic biases.
The Global Burden of Disease (GBD) 2021 study used refined methods to exclude data from passive case-finding sources, which historically underestimated prevalence. By focusing on data from active case-finding approaches and correcting for bias using Bayesian meta-regression (DisMod-MR 2.1), the research achieved a more accurate and inclusive global picture. The exclusion of older, registry-based estimates significantly increased the reported prevalence compared to GBD 2019, aligning more closely with high-quality studies from countries like Japan and South Korea.
In terms of health impact, ASD accounted for 11.5 million disability-adjusted life-years (DALYs) in 2021. These DALYs were composed entirely of years lived with disability (YLDs), as autism was not found to be a direct cause of death in the GBD framework. The condition was ranked among the top ten causes of non-fatal health burden for individuals under 20 years of age worldwide. The age-standardised DALY rate was highest in high-income regions such as Asia Pacific, where Japan exhibited the highest national burden.
Prevalence was highest in early childhood and declined with age, reflecting both diagnostic focus and possible underestimation in older adults due to data limitations. The study emphasized the scarcity of epidemiological data in many regions, especially in low-income countries, and highlighted the need for more representative diagnostic surveys.
An important aspect of this research is its inclusion of people with lived experience in the design and interpretation phases, a progressive step in disability research. Nevertheless, the study also acknowledged its limitations, including reliance on proxy mortality data, challenges in capturing gender identity diversity, and the need for culturally sensitive disability weights.
In conclusion, this study reshapes the understanding of autism’s global footprint. It calls for urgent investment in early detection, lifelong support services, and more inclusive epidemiological research. With one in 127 people affected, the autism spectrum represents a significant public health priority requiring sustained global attention.
Reference: Santomauro, D. F., Erskine, H. E., Herrera, A. M. M., Miller, P. A., Shadid, J., Hagins, H., … & Sankararaman, S. (2025). The global epidemiology and health burden of the autism spectrum: Findings from the Global Burden of Disease Study 2021. The Lancet Psychiatry, 12(2), 111-121.
https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(24)00363-8/fulltext
