Between 2009 and 2017, the percentage of American children and teens aged 3 to 17 who were diagnosed with developmental disabilities rose almost 2 percentage points, to almost 18% from just over 16%, with attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorders (ASD) accounting for most of the increase.
That’s according to a study just published in the journal Pediatrics, part of a periodic survey tracking health trends in the country, conducted by the U.S. National Center for Health Statistics.
According to the study, the prevalence of ADHD rose from about 8.5% to 9.5%, while the incidence of ASD more than doubled, to 2.5% from 1.1%. Also factored into the calculations was an increase in the percentage of young people with intellectual disabilities, to 1.2% from 0.9%.
The authors of the study, titled “Prevalence and Trends of Developmental Disabilities among Children in the United States: 2009–2017,” called the increases “significant.”
The study also indicated that the increase overall was higher in urban areas than in their rural counterparts — 19.5% versus just over 17%. According to the lead researcher for the study, Benjamin Zablotsky, a health statistician with the Centers for Disease Control and Prevention, this may be because rural families might lack access to providers who can treat developmental disorders. Rural areas are particularly affected by a shortage of doctors of all types. These are the states with the fewest (and most) doctors per person.
In addition, according to an article about the study appearing on the ASD news site Spectrum, “Black and Hispanic children are more likely than white children to lack consistent health records and, as a result, be excluded from prevalence estimates.”
It isn’t clear whether the greater prevalence of reported ADHD and ASD cases is necessarily a bad thing. According to Maureen Durkin, a professor at the University of Wisconsin-Madison School of Medicine and Public Health, in an editorial appearing accompanying the study in Pediatrics, greater awareness of the disorders and better diagnosis might be largely responsible for the higher numbers.
Researcher Zablotsky added that a rewording of questions on the survey that yielded the results might also have had an effect.
Scientists at Nashville’s Vanderbilt University are investigating the possibility that antibodies found in the blood of alpacas might hold the secret to curing autism.
By Colman Andrews