New research contradicts RFK Jr.’s claim that severe autism cases are rising

When Health and Human Services Secretary Robert F. Kennedy Jr. announced the government’s new autism findings this month, he painted a grim and highly controversial picture: Not only was autism becoming more prevalent, he said, but “most cases now are severe.”

The notion that severe symptoms are becoming more common isn’t substantiated by scientific evidence. Rather, new research being announced this week at the annual meeting of the International Society for Autism Research in Seattle suggests that the share of autism cases with moderate or significant symptoms remained relatively consistent from 2000 to 2016.

In the past few weeks, Kennedy has repeatedly referred to autism as an “epidemic” that is leading to more cases of severe intellectual disability.

“This is an epidemic like nothing we’ve ever seen before. It dwarfs the Covid epidemic,” he told Fox News this month. “This is disabling children for their entire lives.”

The characterization has sparked outcry among some parents, advocates and medical experts, who say Kennedy is using a minority of cases to represent autism as a whole.

A recent report from the Centers for Disease Control and Prevention found that 1 in 31 children are diagnosed with autism by their 8th birthdays, but it didn’t distinguish between cases with mild or severe symptoms.

Kennedy estimated at an April 16 briefing announcing the findings that a quarter of children diagnosed with autism don’t speak or use toilets without assistance. A previous CDC study found that nearly 27% of people with autism were nonverbal or minimally verbal or had IQs below 50. But many researchers believe the actual rate could be lower — and even then, not all cases have the same limitations.

Autism is a spectrum disorder, meaning it can have a range of manifestations — some mild, others more pronounced — that affect how people socialize, communicate, learn or behave.

The new research being shared this week found that only mild cases rose from 2000 to 2016.

The analysis is based on data from the CDC’s Autism and Developmental Disabilities Monitoring Network, which tracks autism cases across the United States. To determine whether cases were mild or not, the researchers looked at adaptive test scores — interviews that evaluate kids’ social, communication and daily living skills — as opposed to IQ scores, which illustrate intellectual disability.

“There are many kids with autism that have IQ scores that would define them as having intellectual disability, but their adaptive scores are higher,” said a co-author of the research, Maureen Durkin, a professor of population health sciences at the University of Wisconsin-Madison.

David Mandell, a psychiatry professor at the University of Pennsylvania who wasn’t involved in the analysis, said adaptive scores are designed to catch severe cases like the ones Kennedy described. Compared with IQ scores, they offer a better picture of how children with autism function in real life, he said — such as whether they can speak to others, dress themselves or use the bathroom on their own.

According to the analysis, 1.2 out of 1,000 children had autism with moderate or significant impairment in 2016, compared with 1.5 out of 1,000 in 2000. By contrast, mild cases rose 139% during that period — from 3.1 out of 1,000 to 7.3 out of 1,000.

“The increase is in kids who are less severely impaired. It would be really good if the current secretary of HHS knew that,” said Marianne Barton, a clinical professor of psychological sciences at the University of Connecticut, who wasn’t involved in the research.

The Department of Health and Human Services didn’t respond to a request for comment.

One possible explanation for the rise in mild cases, Durkin said, is that doctors have gotten better at identifying mild symptoms. Developmental screenings became more common over the study period, and the American Academy of Pediatrics began recommending universal screenings specifically for autism in 2006.

The diagnostic criteria for autism also changed in 2013 to include milder cases, such as the condition formerly known as Asperger’s.

“We are seeing the extraordinary expansion of the diagnostic criteria to include people who never would have met criteria for autism 50 years ago,” Mandell said.

Dr. Alex Kolevzon, clinical director of the Seaver Autism Center at Icahn School of Medicine at Mount Sinai, said that since the analysis is based on health and school records rather than in-person diagnoses, it’s possible it may include some children with mild symptoms who don’t have autism at all.

“When you look at this group that we are probably pretty confident in the diagnosis, you’re not seeing an increase in prevalence,” he said.

Kennedy has decried that theory, suggesting that only “small slivers” of rising cases are attributable to increased diagnoses.

“The media has bought into this industry canard, this mythology that we’re just seeing more autism because we’re noticing it more,” he told Fox News host Sean Hannity this month.

Instead, Kennedy has said without evidence that an environmental toxin is driving up cases, and he tasked CDC scientists with identifying a catalyst by September — a feat outside researchers say is unrealistic unless the CDC already has a predetermined conclusion.

Kolevzon said that it’s possible that something in the environment could aggravate underlying genetic risks for autism but that existing research hasn’t pointed to any culprits yet.

“We’re not going to discover some sort of widespread environmental factor that explains the increase in prevalence,” he said.

This article was originally published on NBCNews.com