Autism: Could high U.S. rate be due to over-diagnosis?

(CNN)A report from the Center for Health Statistics finds that 13% of children who were diagnosed with autism spectrum disorders lose their diagnosis after later tests. The study, which uses data from the Centers for Disease Control and Prevention, is the first to look at a large, nationally representative sample of children.

One in 68 children in the United States are believed to have an autism spectrum disorder, a 30% increase from earlier estimates; in 2012 it was believed 1 in 88 children were on the spectrum, the CDC says. The diagnosis reversals are important to note for scientists who have puzzled over why there is such a big increase in the number of cases.
Researchers say some children who are given the autism label may in fact be struggling with other challenges, such as developmental delays or attention issues. Of the parents who were surveyed about the reversed diagnoses, about 74% thought the reversals were due to new information, meaning their child started to show developmentally appropriate social skills or language abilities, as opposed to a child being "cured." However, there have been some small studies that show early intervention with a child has shown promise.
    The authors say some reversals may be due to the way children are screened. Pediatricians are encouraged to use developmental screening tests with all children regardless of any signs a child has a problem. Having a nonspecialist diagnose a child may be adding to the increase in numbers; so may an increased awareness about autism spectrum disorder, the authors say.
    Scott Badesch, president and CEO of the Autism Society, agrees. "Better diagnosis occurring, as well as greater awareness of signs of autism being known, is also leading to more people being diagnosed as well," Badesch said. He also agrees with the authors that "additional research is needed before any one or more causes can be positively defined as the reason for the increase."
    More research will be needed to determine if over-diagnosis has become more common, but the work does show that a child's diagnosis can sometimes change as the children get older and doctors learn more about the child.