CHICAGO — A study in South Korea suggests about 1 in 38 children have traits of autism, higher than a previous U.S. estimate of 1 in 100.
By casting a wider net and looking closely at mainstream children, the researchers expected to find a higher rate of autism characteristics. But they were surprised at how high the rate was. They don’t think South Korea has more children with autism than the United States but instead that autism often goes undiagnosed in many nations. U.S. estimates are based on education and medical records, not the more time-consuming survey conducted in South Korea.
Two-thirds of the children with autism traits in the study were in the mainstream school population, hadn’t been diagnosed before and weren’t getting any special services. Many of those undiagnosed children likely have mild social impairments rather than more severe autism.
“It doesn’t mean all of a sudden there are more new children with (autism spectrum disorders),” said co-author Dr. Young-Shin Kim of the Yale Child Study Center. “They have been there all along but were not counted in previous prevalence studies.”
The Centers for Disease Control and Prevention wasn’t involved in the new study, although another federal agency, the National Institute of Mental Health, provided some funding. The group, Autism Speaks, which advocates for more aggressive autism screening, also helped pay for the study. Autism Speaks had no role in the study’s design.
The research, published today in the American Journal of Psychiatry, attempted to screen all 55,000 schoolchildren between ages 7 and 12 in a district of Goyang City, near Seoul.
However, only about two-thirds of mainstream children participated. About 63 percent of their parents filled out a survey. The researchers said that parents of affected children might be more likely to fill out the survey.
The questionnaire used is a recognized screening tool for high-functioning autism such as Asperger’s syndrome. It asks such questions as whether the child “stands out as different” in a number of ways, including lacking empathy, lacking best friends and being bullied by other children.
