Autism Spectrum Disorder: Rising Number of Cases Not Entirely True

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Jul 27, 2015 06:00 AM EDT

Researchers at Penn State University have concluded that the rising rates of autism as reported by the U.S. Centers of Disease Control and Prevention was incorrect. The Penn State study suggests that autism cases are not rising but rather being correctly identified in children previously diagnosed with intellectual disability by healthcare practitioners.

The CDC recently reported that there has been an increasing number of autism cases throughout the years. According to the official Penn State website, 1 in every 5000 children were diagnosed with autism in 1975.

The rate grew to 1 in 150 in 2002, and rose again to 1 in 68 in 2012. The CDC's report has shown that there has been a three-fold increase in autism cases since 2000, which has alarmed the public.

Researchers at Penn State University discovered that the increasing rate of autism in children is due to the fact that more and more healthcare providers are changing their initial diagnosis on children.

The CDC report, it seems, failed to account for children whose doctors may have diagnosed a disorder other than autism, and later discovered that the child was indeed autistic.

In fact, 65 percent of children who were previously diagnosed with intellectual disability have been reclassified as children with autism instead, reports TV News Room.

Due to the increasing information and data healthcare providers have on autism, they are now better equipped to diagnose symptoms of the disorder and correct cases in which children have been incorrectly diagnosed.

Santhosh Girirajan, assistant professor of biochemistry and molecular biology and of anthropology at Penn State, lead the research. He attempted to explain why so many cases of autism might have been incorrectly identified as a different form of developmental disorder.

"For quite some time, researchers have been struggling to sort disorders into categories based on observable clinical features, but it gets complicated with autism because every individual can show a different combination of features," Girirajan said in a university news release.

He went on to say, "The tricky part is how to deal with individuals who have multiple diagnoses because, the set of features that define autism is commonly found in individuals with other cognitive or neurological deficits."

Researchers at Penn State calculated that exactly 59 percent of the observed increase in autism among 8 year-old children was due to reclassification. In addition, researchers concluded that reclassification is 97 percent responsible for the rising autism rate seen in teens.

As more and more autism cases are being correctly diagnosed, there has been a significant decrease in the rate of other developmental disorders seen in children.

Cases of children diagnosed in the emotional disturbance category have dropped by 22 percent, while children identified with certain learning disabilities have decreased by 19 percent.

Girirajan advised: "...Every patient is different and must be treated as such. Standardized diagnostic measures incorporating detailed genetic analysis and periodic follow up should be taken into account in future studies of autism prevalence."

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