The clinical definition for when a child has some form of autism has been tightened. And these narrower criteria for autism spectrum disorder probably will reduce the number of kids who meet the new standard.
But researchers say the changes, which were rolled out last May, are likely to have a bigger effect on government statistics than on the care of the nation's children.
Results from the government study published last week found that about 19 percent of 8-year-olds previously classified as having an ASD didn't meet the updated criteria from the latest edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-5. The results suggest the government's estimate that 1 in 88 children has an autism spectrum disorder could be reduced to 1 in 100.
DSM-5 eliminates separate diagnostic labels for problems like Asperger's. It also changes the way specific symptoms are used to reach a diagnosis.
The study findings have got some advocacy groups worried that children will lose care and support services. "This raises serious concerns," says a statement from Rob Ring on the Autism Speaks website. The group says it has found examples of children losing autism services because their diagnosis was changed.
A South Korean study, funded in part by Autism Speaks, found that previously diagnosed children who didn't fit the new autism criteria would instead be diagnosed with the newly created social communication disorder, which would likely qualify them for services.
But Roy Richard Grinker of George Washington University doesn't think that's going to happen to a lot of kids. The DSM-5 will be used primarily in research settings, where "diagnoses are based on rigorous application of criteria," he says. "In everyday life, diagnoses may be made for short or long-term benefits, like helping a child get into a classroom environment that will help him or her."
The people who actually assess kids with social interaction problems or repetitive behaviors usually aren't focused on the DSM-5 criteria, Grinker says. Instead they are asking, "What is the best set of services for this person?" and, "What diagnosis should I give the person to get him or her those services?"
So even if the government lowers its estimate of children with an autism spectrum disorder, Grinker says, there could still be an increase in number of kids across the country who receive an autism diagnosis from a local clinician.
The new study confirms that "the overwhelming majority" of children diagnosed with an autism spectrum disorder under the old criteria will also meet the new criteria, says pediatrician Susan Hyman of the University of Rochester.
And the new criteria may actually help some kids qualify for additional services because DSM-5 no longer prohibit clinicians from adding problems such as ADHD to an autism diagnosis, Hyman says.
But "the jury is out on the DSM-5," Hyman says. "It might be more accurate. It might just be different."
In the meantime, she says, researchers need the more rigorous diagnostic criteria of DSM-5 because it will help them identify the underlying brain changes associated with autism spectrum disorders. And until scientists find good biological markers of autism, Hyman says, we won't know how many children truly have the disorder.