One in 6 US children has developmental disabilities

Developmental disabilities are on the rise, with significant increases in autism and attention-deficit/hyperactivity disorder (ADHD), according to results from a new study reported in Pediatrics.

Researchers from the National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, studied information collected from the 1997 to 2008 National Health Interview Surveys. They focused on parent-reported diagnoses of developmental disabilities (ADHD, autism, “mental retardation,” cerebral palsy, seizures, stuttering or stammering, hearing loss, blindness, learning disorders, and other developmental delays) in children who were 3 to 17 years of age. The sample size included 119,367 children.

The occurrence of developmental disabilities increased 17.1%, from 12.84% to 15.04%, over the study period from 1997 to 2008. The rate of any developmental disability was 13.87%, ranging from 0.13% for blindness and 3.65% for other developmental delays to 6.69% for ADHD and 7.66% for learning disabilities.

The upward trend in developmental disabilities was primarily because of a 33% increase in ADHD. Autism, however, had the largest relative increase at 289.5%, rising nearly 4-fold from 0.19% to 0.74%. Other developmental delays increased 24.7%.

In general, boys were more likely than girls to have disabilities (18.04% vs 9.50%) and more apt to have a diagnosis of ADHD (9.51% vs 3.73%). Children insured by Medicaid and from low-income homes tended to have higher rates of certain disabilities.

The researchers found that 15% of children aged 3 to 17 years, or nearly 10 million children from 2006 to 2008, had a developmental disability on the basis of parent report. The 17% increase in prevalence over the 12-year period represents approximately 1.8 million more children with developmental disabilities from 2006 to 2008 than a decade earlier, they say.

Boyle CA, Boulet S, Schieve LA, et al. Trends in the prevalence of developmental disabilities in US children, 1997-2008. Pediatrics. 2011. Epub ahead of print.