The Grapevine

Autism Spectrum Disorder: Prevalence Rate Increases To 1 In 45 Children, But Are We Getting The Diagnosis Right?

1 in 45
Are rates of ASD really increasing, or are we just starting to recognize and diagnose more cases? April Moore-Harris (CC BY-NC-ND 2.0)

About one in 45 children in the U.S. have an autism spectrum disorder (ASD), according to the latest National Health Interview Survey by the Centers for Disease Control and Prevention. Although this is a significant increase from the CDC’s previous estimate — one in 68 children — the data forming the basis for this estimate came from a survey that was formatted differently than the current one. Experts suggest several reasons for the uptick in ASD rates, none of which actually include more cases of the condition.

Survey Format

The previous survey, used between 2011 and 2013, was far less focused on ASD than the current survey, according to Benjamin Zablotsky, an epidemiologist in the Division of Health Interview Statistics at the National Center for Health Statistics in Hyattsville, Md. It asked parents if their child had ever been diagnosed with an intellectual disability, then asked about other developmental delays, and required parents to look at a list of 10 conditions and indicate whether a health professional had ever told them their child had one.

The second version of the survey included a stand-alone question about ASD: Parents were asked if their child had ever been diagnosed with autism, Asperger’s disorder, pervasive development disorder, or autism spectrum disorder. This approach may have eliminated the possibility that autism got lost in the shuffle of a list Zablotsky explained to Fox News.

Increased Awareness, Decreased Stigma

One possible reason for the increase in ASD cases is that parents are more aware of the disorder than ever and are changing the way they label their children. Growing awareness of ASD may have contributed to the number of children diagnosed with autism going up and the figure for children diagnosed with “other developmental delays” going down. Overall, the number of parents who reported any type of developmental disability in their children remained the same, at about 5.75 percent.

According to Robert Fitzgerald, an epidemiologist in psychiatry at the Washington University School of Medicine in St. Louis, awareness of ASD has increased in both parents and health care providers. He told Fox News that in the past, kids with ASD may have been misdiagnosed as having an “intellectual disability,” and that recent changes in the diagnostic criteria used to describe ASD may have changed the way diagnosis occurs.

Fitzgerald suggested a second reason for the increase in ASD prevalence is a decrease in the stigma surrounding it. In the past, even doctors were hesitant to label a child autistic, which led to that child’s medical records having been labeled with an underdiagnosis or misdiagnosis. Now that there has been an increase in support and services for children with ASD, doctors and parents are in a different mindset.

What’s The Big Deal?

The difference between an intellectual disability and ASD may not seem like much to an outsider, but there are several important differences between the two diagnoses. An intellectual disability is characterized by limitations in intellectual functioning and in adaptive behavior. Intellectual functioning — also known as intelligence — refers to the mental capacity of a child and is measured by an IQ test. A score of around 70-75 indicates a limited intellectual functioning. Adaptive behavior is the group of social, practical, and conceptual skills learned and performed by people in everyday life. These include language and literacy, the ability to follow rules, understanding of money, and the concept of problem solving.

ASD, however, is characterized by difficulty in developing social and communication skills, sometimes accompanied by repetitive behavior. Though up to 70 percent of people with ASD are also affected by another condition (including intellectual abilities), they are not synonymous and are not always seen together.

There is no cure for ASD, but there are some medications that can treat symptoms of the disorder, such as inability to focus, too much energy, and depression. For children with intellectual disabilities, services are primarily social and supportive in nature. The misdiagnosis of a child with ASD could result in that child not receiving the treatment and medication they need, which could severely impact their quality of life.

Results from the last 10 years of measuring ASD prevalence have not yet shown a leveling off, according to Fitzgerald. It will be important to monitor if the U.S. continues to see an increase in autism cases.

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