OARacle Newsletter

An estimated 61.8 million people, or one in 127, around the world were autistic in 2021, according to new data from the Global Burden of Disease Study 2021 recently published in The Lancet. As noted on the Learning Disability Today website, this estimate is substantially higher than the 2019 estimate of one in 271. While that seems concerning, the researchers explained in The Lancet article that the difference is mainly due to changes in how the Global Burden of Disease Study estimated prevalence in 2019.

Additionally, researchers found that autism ranked among the top 10 causes for non-fatal health burden for people younger than 20 years old. Researchers emphasized in their article that this finding highlights the need for early detection and developmental support for autistic people. They went on to note that “most epidemiological investigations into autism have focused on children and adolescents, leaving a gap in our understanding of the autism spectrum in adults. The prevalence and health burden of autism spectrum disorder persisted across the lifespan, beginning to decline from age 60 years.”

The data also showed that autism affects double the number of males, at 1,065 cases per 100,000 males, compared to females, 508 cases per 100,000 females. Findings also highlighted a substantial variance in prevalence by region, from one in 163 people in Latin America to one in 65 people in Asia Pacific. Many factors contribute to the geographical variations, the researchers noted, including variances in exposure to risk factors, cultural differences in behavioral norms, validity, screening and diagnostic tools, how participants respond to survey questions, and even their choice to participate.

The increase in prevalence found in the 2021 study is lower than the findings of the Centers for Disease Control and Prevention, which found that one in 36 eight-year-old children were autistic in the United States in 2020, as noted in The Lancet article. This higher prevalence was determined from a review of case notes to establish if a child met diagnostic criteria. The children were not clinically evaluated for autism, which could have caused an overestimation of prevalence.

The Global Burden of Disease Study is the “single largest and most detailed scientific effort ever conducted to quantify levels and trends in health,” according to the Institute for Health Metrics and Evaluation at the University of Washington, which houses the study.

“The persistence of autism’s health burden across a lifespan, including adulthood, demands a shift in how health systems respond to autism, emphasizing the importance of inclusive and accessible health care services,” said Dr. Damian Santomauro, an affiliate assistant professor at the Institute who led the study. The research team, he said, hopes that the study “provides a foundation for future research and policy interventions so the key stakeholders work to ensure that the unique needs of all autistic persons are met, and contributes to a better and more inclusive and understanding future.”

Sherri Alms is the freelance editor of The OARacle, a role she took on in 2007. She has been a freelance writer and editor for more than 20 years.