MONDAY, May 23, 2011 (Health.com) — The proportion of children and teens in the U.S. who have been diagnosed with a developmental disability such as autism has increased 17% since the late 1990s, according to a new report from the Centers for Disease Control and Prevention (CDC).
Between 1997 and 2008, the number of children diagnosed with a disability rose from 8.2 million to roughly 10 million, or more than 15% of all kids between the ages of 3 and 17, the researchers found.
This upward trend has been driven largely by surges in the number of children diagnosed with autism and attention deficit hyperactivity disorder (ADHD), although the prevalence of stuttering and learning disabilities has also increased.
The study, which appears in the June issue of the journal Pediatrics, is the first time nationally representative data on developmental disabilities has been collected since 1988, says Sheree Boulet, DrPH, one of the study’s authors and an epidemiologist at the CDC’s National Center on Birth Defects and Developmental Disabilities.
The reasons for the increases aren’t clear, but growing awareness and increasing acceptance of developmental disabilities have probably played a big role, Boulet says. For instance, she explains, the availability of early and effective treatments for conditions such as ADHD might be encouraging more parents to have their children screened for the disorder.
The study findings are to be expected, given the “increased awareness and much better reporting,” says Alan Hilfer, PhD, the director of psychology at Maimonides Medical Center, in New York City. (Hilfer was not involved in the new research.)
At the same time, the occurrence of disabilities may be genuinely increasing. A shift toward having babies later in life, more premature births, and growing use of fertility treatments—all of which are risk factors for developmental disabilities—could be contributing to the higher rates, the researchers say.
The findings “suggest that there are some more prevention strategies that could be put into use,” Boulet says.
The study was based on nationally representative health surveys that included in-person interviews with nearly 120,000 children across the country. During the interviews, the researchers asked parents whether their kids had been diagnosed with autism, ADHD, learning disabilities, cerebral palsy, seizures, stuttering or stammering, hearing loss, blindness, or intellectual disability (formerly known as mental retardation).
The overall disability rate rose from about 13% to just over 15% during the 12-year study period. In 2008, the most common disabilities were ADHD (7.6%) and learning disabilities (7.2%). Roughly 0.75% of children had been diagnosed with autism, up from 0.19% in 1997.
The only disability to decrease was moderate-to-profound hearing loss, which went down 31%.
Next page: Striking gender and ethnic differences
