Uptick Autism rate rises slightly; RFK Jr. claims he’ll “have answers by September“ The slight rise is due to better access to tests in underserved communities. Beth Mole – Apr 15, 2025 6:09 pm | 15 The Centers for Disease Control and Prevention (CDC) headquarters stands in Atlanta, Georgia, on Saturday, March 14, 2020. Credit: Getty | Bloomberg The Centers for Disease Control and Prevention (CDC) headquarters stands in Atlanta, Georgia, on Saturday, March 14, 2020. Credit: Getty | Bloomberg Story text Size Small Standard Large Width * Standard Wide Links Standard Orange * Subscribers only   Learn more The rate of autism in a group of 8-year-olds in the US rose from 2.76 percent (1 in 36) in 2020 to 3.22 percent (1 in 31) in 2022, according to a study out Tuesday in the Morbidity and Mortality Weekly Report, a journal published by the Centers for Disease Control and Prevention. The report's authors—researchers at the CDC and academic institutions across the country— suggest that the slight uptick is likely due to improved access to evaluations in underserved groups, including Black, Hispanic, and low-income communities. The data comes from the CDC-funded Autism and Developmental Disabilities Monitoring (ADDM) Network. The national network has been tracking the prevalence of autism spectrum disorder (ASD) in 8-year-olds at a handful of sites since 2000, publishing estimates every two years. In 2000, ASD prevalence was 1 in 150, with white children from high-income communities having the highest rates of the developmental disability. In 2020, when the rate hit 1 in 36, it was the first year in which higher ASD rates were seen in underserved communities. That year, researchers also noted that the link between ASD and socioeconomic status evaporated in most of the network. In the new data, prevalence continued to be higher in underserved communities compared with white children. Prevalence among white children was 27.7 per 1,000, which is lower than prevalence among multiracial (31.9), Hispanic (33.0), Black (36.6), American Indian or Alaska Native (37.5), or Asian or Pacific Islander children (38.2). And, overall, prevalence was higher among children from low-income neighborhoods. "The reversal of these patterns in prevalence by race and ethnicity and SES [socioeconomic status] is consistent with increased access to and provision of identification services among previously underserved groups," the researchers conclude. A look forward also shows trends toward more and earlier access to services. While monitoring has focused on 8-year-olds because children are more likely to have a diagnosis by that age, the researchers also examined autism evaluations and rates among children who were 4 years old in 2022. Researchers found that the younger children, born in 2018, had more evaluations in the same age window as the children who were born in 2014. Disparities This year, the ADDM included 16 sites across the country—in many past years, there were 11 sites. It's important to highlight that although the prevalence rates from these sites are often seen as national estimates of ASD prevalence, they are not. These 16 sites are not nationally representative. The populations within ADDM "do not generate nationally representative ASD prevalence estimates," the authors caution. Among the sites, there were large differences. Prevalence ranged from 9.7 per 1,000 children who were 8 years old in Texas (Laredo) to 53.1 in California. These differences are likely due to "differences in availability of services for early detection and evaluation and diagnostic practices," the CDC and network researchers wrote. For instance, California—the site with the highest prevalence among 8-year-olds and also 4-year-olds—has a local initiative called the Get SET Early model. "As part of the initiative, hundreds of local pediatricians have been trained to screen and refer children for assessment as early as possible, which could result in higher identification of ASD, especially at early ages," the authors write. "In addition, California has regional centers throughout the state that provide evaluations and service coordination for persons with disabilities and their families." On the other hand, the low ASD rates at the network's two Texas sites could "suggest lack of access or barriers to accessing identification services," the authors say. The two Texas sites included primarily Hispanic and lower-income communities. The newly revealed higher rates in some of the network's underserved communities could link ASD prevalence to social determinants of health, such as low income and housing and food insecurity, the authors say. Other factors, such as higher rates of preterm birth, which is linked to neurodevelopmental disabilities, as well as lead poisoning and traumatic brain injuries, may also contribute to disparities. Anti-vaccine voices The detailed, data-heavy report stands in contrast to the position of health secretary Robert F. Kennedy Jr., a longtime anti-vaccine advocate who promotes the false and thoroughly debunked claim that autism is caused by vaccines. Last month, Kennedy hired the discredited anti-vaccine advocate David Geier to lead a federal study examining whether vaccines cause autism, despite numerous high-quality studies already finding no link between the two. Geier, who has no medical or scientific background, has long worked with his father, Mark Geier, to promote the idea that vaccines cause autism. In 2011, Mark Geier was stripped of his medical license for allegedly mistreating children with autism, and David Geier was fined for practicing medicine without a license. In a media statement Tuesday in response to the new report, Kennedy called autism an "epidemic" that is "running rampant." He appeared to reference his planned study with Geier, saying: "We are assembling teams of world-class scientists to focus research on the origins of the epidemic, and we expect to begin to have answers by September." Beth Mole Senior Health Reporter Beth Mole Senior Health Reporter Beth is Ars Technica’s Senior Health Reporter. Beth has a Ph.D. in microbiology from the University of North Carolina at Chapel Hill and attended the Science Communication program at the University of California, Santa Cruz. She specializes in covering infectious diseases, public health, and microbes. 15 Comments