Autism rates rose again between 2018 and 2020, the most recent year data is available, up from 1 in 44 children to 1 in 36.
Many factors are likely to contribute to these rising rates, including that diagnoses among children of color have been catching up to – and are now passing – white children.
With conditions that require a complicated diagnostic process, it's typical for less advantaged children to lag behind, so the increase suggests more children of color are now getting the help they need, said Andy Shih, chief science officer of Autism Speaks, an advocacy group.
"This increase is really fueled by us doing a much better job in identifying minority children with autism," Shih said.
But Walter Zahorodny, an author on the paper, said he thinks there's more going on than just better identification.
"No one really knows what's driving autism rates higher," said Zahorodny, also director of the New Jersey Autism Study and an associate professor at Rutgers University.
For years, people have pinned rising rates on a variety of causes, including improved awareness, reduced stigma, re-labeling of kids, aging parents, low-birth-weight babies or C-section deliveries. Though they all may contribute, Zahorodny thinks something else from our contemporary environment is driving the rates.
"This is a true increase," he said. "It constitutes a major public health crisis."
Autism diagnoses rates increase: What does that mean for schools?
What is autism spectrum disorder?
Autism spectrum disorder is diagnosed based on challenges with social skills, communication and repetitive behaviors. It is a spectrum, meaning symptoms vary widely, with a percentage unable to communicate at all and others highly successful in some areas of life.
Autism rates and disparities: What the data shows
In 2000, 1 in 150 children was diagnosed on the autism spectrum. The latest data shows 1 in 36 has the condition.
The prevalence among 4-year-olds jumped 26% between 2018 and 2020, increasing even more in girls than boys, though boys are still about four times more likely to receive a diagnosis than girls.
For the first time, data published Thursday found that white children are less likely to carry the diagnosis than children of color. Here's the breakdown of autism diagnoses rates among 8-year-olds:
3.3% of children of Asian or Pacific Island descent.
3.2% of Hispanic descent.
2.9% of Black children.
2.4% of white, non-Hispanic children.
The data is drawn from 11 communities nationwide that belong to the Autism and Developmental Disabilities Monitoring Network. They are not representative of the entire country but are used as a proxy.
Autism and intellectual disabilities: What the data shows
The racial disparity also extends to the diagnosis of intellectual disability along with autism. Almost half of Black children with autism were also diagnosed with intellectual disability compared with about 30% of children with autism who are white.
This suggests Black children with autism but not intellectual disability are still being missed, Shih said.
"We're probably undercounting more mildly affected kids in minority populations," he said, which means losing the opportunity to provide services that can help change their trajectories. "They're invisible to the system still."
Children without intellectual disabilities also tend to be diagnosed with autism later.
"Inequity introduced at this point in life will persist and only widen over time," Shih said.
How the pandemic impacted autism diagnoses and services
The pandemic also disrupted autism diagnoses for 4-year-olds, according to another paper published Thursday in the Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report.
Three years ago during the early months of COVID, 4-year-olds were less likely to be evaluated for or diagnosed with autism than 8-year-olds had been at the same age. It's not clear how quickly evaluations rebounded as the pandemic unfolded.
Such delays in diagnosis could have long-lasting effects, said Dr. Karen Remley, director of CDC’s National Center on Birth Defects and Developmental Disabilities, in a prepared statement.
“The data in this report can help communities better understand how the pandemic impacted early identification of autism in young children and anticipate future needs as these children get older,” she said.
When is autism diagnosed? Looking for early signs and symptoms
Despite increased attention, most children are still not diagnosed with autism until they are nearly 4, a figure that has not budged, Zahorodny said.
Universal screening is recommended for toddlers at their 18- and 24-month well child visits. But in many places, there is no follow-up from that medical visit or services provided until a child reaches school age, he said, which means a missed opportunity to intervene early.
Early intervention certainly does no harm, Zahorodny said, and "if you give them good resources, they improve to a higher level and have a better quality of life and more functionality."
EARLY DIAGNOSIS: How a new algorithm can detect signs of autism in infants
What is driving rising rates of autism?
Rates vary widely across states, with California reporting rates more than two-and-a-half times higher than Utah.
Experts don't think that reflects a fundamental difference, but rather demographic differences and the greater access to services in California, especially for young children, which encourages parents to seek support for their child.
San Diego, more than any other community of the 11 surveyed, has set up a system for identifying children with autism early and getting them services, Zahorodny said. That might be the ideal elsewhere, but doesn't happen consistently, he said.
Improved services definitely help drive rates up, Shih said, which is a good thing.
"We're definitely seeing there's a greater capacity among caregivers and families not only to recognize and to understand what autism is but also to navigate the system," he said. "I think that's a huge improvement and progress in our community."
Contact Karen Weintraub at email@example.com.
Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.
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This article originally appeared on USA TODAY: US autism rates increase; kids of color more likely to have diagnosis