New research shows that the childhood autism rate may be much higher than previously thought-1 in 38, up from 1 in 110-but it doesn't necessarily mean that autism is on the rise.
The latest study, published Monday in The American Journal of Psychiatry, followed children in a middle-class South Korean city for six years and found that 2.6 percent of children age 7 to 12 in the city of Goyang had some form of Autism Spectrum Disorder.
"That is two-and-a-half times what the estimated prevalence is in the United States," one of the study's authors, Roy Richard Grinker, a professor of anthropology at George Washington University, told NPR. "Two-thirds of the children with autism that we ended up identifying were in mainstream schools, unrecognized, untreated."
According to the National Institutes of Health, "Autism is a complex developmental disability that causes problems with social interaction and communication. Symptoms usually start before age three and can cause delays or problems in many different skills that develop from infancy to adulthood." It is not a mental illness, it's a neurobiological issue. No one knows what causes autism spectrum disorders; though a link between vaccines and autism has been thoroughly debunked, several other theories (environmental toxins, genetics) remain.
The current 1-in-110 rate was calculated by studying children who have already been identified as having learning or language problems, or who are already in special-education classes. This time, researchers studied the entire population of Goyang instead-about 55,000 children, including those in mainstream schools. The results raise questions about how the autism rate in the U.S. might change if all children were screened for the disorder.
"It doesn't mean all of a sudden there are more new children with (autism spectrum disorders)," co-author Dr. Young-Shin Kim of the Yale Child Study Center told The Washington Times. "They have been there all along, but were not counted in previous prevalence studies."
"From the get-go we had the feeling that we would find a higher prevalence than other studies because we were looking at an understudied population: children in regular schools," the lead researcher, Dr. Young-Shin Kim, a child psychiatrist and epidemiologist at the Yale Child Study Center, told the New York Times.
The study, which was financed in large part by the advocacy group Autism Speaks, focused on South Korea "not only because autism prevalence had not been measured there, but also because its national health care system, universal education and homogeneous population made it a promising region for a planned series of studies that will also look at genetic and environmental factors in autism," The New York Times reported. Researchers first asked parents and teachers to complete a 27-page questionnaire about each child; children who scored within a certain range were then evaluated in person.
Autism is severely stigmatized in South Korea, Kim pointed out. Many of the children didn't misbehave and they weren't failing academically, Kim says-two factors that helped their parents ignore other possible signs of the disorder.
"These children could function at a level that was expected, even though they were having a lot of difficulties with their peers and social engagement," she said. South Korean schools are highly structured, with strict routines and an emphasis on memorization, which could also help children with autism spectrum disorders blend in.
What are some of the red flags to watch out for? According to autism advocate Mika Bradford of AutismSpot, many of the warning signs can appear before the child is 18-months old. Parents who notice the following should speak with their child's pediatrician about an autism screening:
- Slow language development.
- Loss of words the child was once able to speak.
- Unable to follow simple commands.
- Child looks away when you speak to him.
- Does not answer to her name.
- Suspected hearing loss.
- An unusually long attention span.
- Seems off in his own world.
"Some of the parents were yelling at us like, 'You guys are crazy, my child is OK,' " she told NPR. "Some parents are shocked. Some are devastated. But some are like, 'Oh, my God, now it makes sense. Actually, I'm so glad you told me that because I couldn't make any sense out of my child.' "
Also on Shine: