A new report released by the Centers for Disease Control and Prevention on Thursday suggests that the autism rate among children in the US is continuing to rise.
Looking at 8-year-olds in 11 states, the agency found that roughly 1 in 59 fit the autism diagnosis criteria in 2014, up from 1 in 68 in 2012. Boys were about four times more likely to be identified with autism spectrum disorder than girls.
Autism begins in early childhood and can cause social, behavioral, and communication difficulties. Its specific causes are not entirely understood, though it has a significant genetic component.
Experts at the CDC attribute the increase to better awareness and identification of the disorder, especially among black and Latino children who were previously underrepresented in federal counts. In 2012, autism prevalence among white kids was 20% higher than black kids and 50% higher than Latino children. By 2014, those gaps closed significantly, with white rates about 10% higher than black children and 20% higher than Latino kids.
“We don’t have any reason to think there is a biological basis for difference in autism prevalence based on race and ethnicity,” said Daisy Christensen, who leads autism surveillance at the CDC's National Center on Birth Defects and Developmental Disabilities. “So it’s actually encouraging to see those numbers become closer to the prevalence among white children, because we think this indicates these kids are being evaluated and diagnosed, and that may allow them to receive services.”
The autism rate in the US has been steadily climbing since CDC first began its nationwide count in 2000. That year, the reported rate was 1 in 150. The rising prevalence has been largely attributed to increasing awareness of the disorder among parents, teachers, and doctors, as well as more resources for children who are diagnosed.
“It’s a way of counting that is erring on the positive, trying to avoid missing kids,” Catherine Lord, a professor of psychology at Weill Cornell Medicine, told BuzzFeed News.
“But people should not panic that autism is spreading somehow,” Lord said. “All the data that we have suggest so far that right now, primarily what we’re doing is picking up more subtle diagnoses, not that the actual incidence of autism is increasing.”
The 2014 data were based on school and medical records of 263,775 children in 11 states: Arizona, Arkansas, Colorado, Georgia, Maryland, Minnesota, Missouri, New Jersey, North Carolina, Tennessee, and Wisconsin. Autism rates varied widely by state, from roughly 1 in 76 in Arkansas to 1 in 34 in New Jersey.
Arkansas was the only state that collected data from the entire state, including rural areas, as opposed to specific sites. That may have led to a lower estimate compared to states like New Jersey, where the kids were clustered in urban areas that have diagnostic and testing facilities for children with developmental concerns, CDC’s Christensen noted.
Some experts argue that the CDC’s methods for estimating autism prevalence may be misleading. Originally designed in the late 1990s when autism was a less-known diagnosis, the agency’s approach may now be overcounting kids with ASD by relying on school and health records instead of in-person evaluations, said David Mandell, a professor of psychiatry at the University of Pennsylvania Perelman School of Medicine.
“I’d love to see the energy that’s put into doing this count every two years be put into improving the service system for people with autism, rather than conducting the same study over and over with the same inherent flaws," Mandell said.
“It brings a tremendous amount of attention to the disorder, and research dollars,” he added. “But I think it creates a tremendous amount of anxiety.”