LOS ANGELES – One in every six American children now has a developmental disability, a 15 percent increase since 1997, the Centers for Disease Control and Prevention reported Monday. The increase is due almost entirely to an increase in the prevalence of attention-deficit hyperactivity disorder and is based on reports by parents during a telephone survey, researchers reported in the journal Pediatrics.
But because ADHD has become a catchall phrase for a variety of behavioral problems in schools and elsewhere, it is not clear whether the increase represents a real upsurge in such developmental delays or simply parental and physician attribution of old behaviors to a disorder that might be treated with drugs.
The data came from the 1997-2008 National Health Interview Surveys, annual telephone surveys in which interviewers question a representative sample of households about health issues. Parents were asked if their children ages 3 to 17 had been diagnosed with ADHD, intellectual disability, cerebral palsy, autism, seizures, stuttering or stammering, moderate to profound hearing loss, blindness, learning disorders or other developmental delays of any sort.
In 1997-’99, 12.84 percent of children were reported to have such a disability. By 2006-’08, that proportion had risen to 15.04 percent, an increase of 1.8 million that brought the total number of affected kids to nearly 10 million. The bulk of that increase was accounted for by ADHD, up from 5.7 percent to 7.6 percent. The rate of autism also showed a significant increase, up from 0.19 percent to 0.74 percent. Profound hearing loss declined slightly, but the rate of most other problems remained constant. The general category “other developmental delays,” however, showed an increase from 3.4 percent to 4.24 percent.
Boys had the lowest prevalence for most disabilities, while low-income families and those with public-health insurance had the highest prevalence. Hispanic children had the lowest rates of most disabilities.
Some of the increase in disabilities may be due to advancing medical technology. Parents are increasingly being given assistance to have children at older ages, which may increase the risk of problems, and growing numbers of children are being born through assisted reproduction technology, which also involves risks. Better technology is also increasing the survival of children born prematurely, and such children have a much higher risk of developing developmental problems.