In 2000, a diagnosis of autism was relatively rare. About one in 150 children in the United States were found to be on the spectrum. Today, the number is closer to one in 31.

That is the striking conclusion of a new study published by the Centers for Disease Control and Prevention in their Morbidity and Mortality Weekly Report on April 15. Covering data from 2022, the study shows the highest reported prevalence of autism in U.S. children so far — and for many scientists, a clearer picture of autism’s true reach.

“The thing I think that everyone can state, without question or controversy, is that the work really does highlight how unbelievably common autism now is across communities in the U.S.,” Zachary Warren, a clinical psychologist at Vanderbilt University Medical Center and a coauthor of the report, told Science News. “I think we should be doubling our commitment towards finding answers and for building better services.”

For many scientists, the numbers reflect progress: broader diagnostic criteria, earlier screenings, and growing awareness are allowing more children to get the help they need.

But as the numbers rise, so do the exaggerations, gross misunderstandings, and fear-mongering. Nothing new here, although what’s novel is that such attitudes are now part of the official narrative. In an April 16 news briefing, Robert F. Kennedy, Jr., Secretary of the U.S. Department of Health and Human Services, described the trend as an “epidemic” that “tears families apart.”

His comments drew swift criticism from the Autistic Self Advocacy Network, which issued a statement condemning the portrayal. “Treating us like a disease or a burden on society, instead of living people who exist and have our own thoughts and ideas about our disabilities, weaponizes pity and fear to deny our basic rights,” the organization said.

A Growing, Complicated Picture

The CDC’s new data, collected from 16 U.S. locations, shows that among 8-year-olds, autism spectrum disorder (ASD) was diagnosed at a rate of 32.2 per 1,000 children. This represents a small but consistent uptick from 2020, when the rate was about 1 in 36.

“Prevalence varied widely across the 16 sites — from 1 in 103 in Texas (Laredo) to 1 in 19 in California — which could reflect differences in availability of services for early detection, evaluation, and diagnostic practices in each community,” Dr. Karyl Rattay, director of CDC’s division of human development and disability, told ABC News.

In this latest report, ASD was more commonly diagnosed among children of color than white children — a reversal from previous studies. Asian, Black, Hispanic, and multiracial children all had higher diagnosis rates compared to white children.

The gender differences persist, however: boys were 3.4 times more likely to be diagnosed with autism than girls. This ratio has remained more or less constant across years of reporting. But crucially, the new report emphasized that only a minority — fewer than 40% — of those diagnosed had intellectual disabilities.

The autism spectrum, experts stress, is extremely wide. Some children require intensive support, while others live independently with minimal assistance.

“This increased rate is driven by a few factors including improved awareness of autism amongst clinicians, parents, educators and other professionals; improved access to screening and evaluation; and expanded diagnostic criteria for autism,” said Roma Vasa, director of psychiatric services at the Kennedy Krieger Institute.

Indeed, part of the rise stems from the broader redefinition of autism in 2013, when diagnoses such as Asperger’s syndrome were folded into the broader ASD category.

“There’s no one true presentation of autism,” said. “Autism, fundamentally … is a word that we use as our best attempt to describe and understand these uniquely wonderful kids that have strengths, but also some tremendous areas of vulnerability and impairment.”

Why Are Autism Rates Rising?

Scientists are careful to separate what they know from what remains uncertain.

“It doesn’t matter if you take the CDC report or insurance claims data — you find this literally doesn’t matter which country you look at or which timeframe; the numbers steadily go up,” Juergen Hahn, a biomedical engineer at Rensselaer Polytechnic Institute, told Newsweek.

Hahn, like others, sees no single explanation. Some factors — such as older parental age, better survival rates among preterm infants, and greater exposure to environmental risks — may play a role. But none seem large enough individually to account for the dramatic rise.

“Everyone wants it to be simple,” Warren said. “But the answers are supercomplex, and in part, they’re supercomplex because autism itself is supercomplex.”

Some researchers, such as neuroscientist Robert Melillo, argue that only about 50% of the increase can be explained by better recognition. “That means at least 50 percent has no explanation,” he told Newsweek, adding that growing numbers of children with all developmental disabilities are evident in both education and healthcare systems.

Yet others, like Nigel Newbutt from the University of Florida, urge more restraint. Instead of panicking over rising numbers, society should concentrate on making schools, workplaces, and communities more inclusive. “More importantly, and regardless of diagnosis rates or vaccine skepticism, we need to build greater understanding, provide better services, and support more inclusive and respectful environments to allow autistic groups to thrive,” Newbutt said.

Meanwhile, Robert F. Kennedy Jr. has amplified calls for environmental investigations, saying, “Genes do not cause epidemics. They can provide a vulnerability, but you need an environmental toxin.”

Many researchers caution against framing autism as an “epidemic.” Amy Gravino, an advocate at Rutgers University, put it bluntly: “We’ve always been here, even if we haven’t been counted in the CDC prevalence rate throughout history. I would just love to see a fuller kind of picture of what autism actually is outside of one narrow presentation that applies to one narrow specific group of individuals.”

Gravino warned against losing sight of the human stories behind the numbers. “Behind every statistic is a family, is a life, is someone trying to exist in this world that isn’t built for people who are like us,” she said.

“The biggest thing is for people to be able to live their life fully, and for them to have a high quality of life,” said Landa from the Kennedy Krieger Institute. “We’ve made a lot of discoveries that have improved the quality of life of autistic people. And yes, we have a long way to go, but we’ve come a long way, too.”