NEW YORK – The U.S. prevalence of attention-deficit/hyperactivity disorder among children and adolescents rose to its highest level in 2007-2008, with 9.5% of children and adolescents ever diagnosed, according to a federally sponsored national telephone survey covering more than 70,000 American children and adolescents.
Although the reasons behind the increased prevalence of attention-deficit/hyperactivity disorder (ADHD) remain unclear, the increase over the 7.8% rate of ever diagnosed ADHD in 2003-2004 reached statistical significance and appears real.
"We think something is going on," Melissa L. Danielson said while presenting a poster at the annual meeting of the American Academy of Child and Adolescent Psychiatry. Explanations might include increased awareness of the diagnosis, and more children and adolescents undergoing formal evaluation, she said. Backing up the national finding are the data on ADHD prevalence in each individual state. Prevalence rates have been up in almost every state, and in 13 states recent increases reached statistical significance, she said in an interview.
The National Survey of Children’s Health, run by the Centers for Disease Control and Prevention, receives its primary funding from the Department of Health and Human Services. In 2007 and 2008, a randomly selected sample of U.S. parents answered a telephone survey about their children’s health. Parents answered four questions about ADHD: Did they have a child aged 4-17 years who ever received a diagnosis of disorder? Did their child have a current diagnosis? Is the ADHD mild, moderate, or severe? Does the child receive medication?
Extrapolated survey results showed that in 2007-2008, 4.1 million American children and adolescents had a current diagnosis, 7.2% of the 4- to 17-year-old population (less than the 9.5% ever diagnosed with ADHD). Of these, two-thirds – 2.7 million – received medical treatment for their ADHD, and parents said that 570,000 (14%) of their kids had severe ADHD. About half had mild ADHD, with the remaining patients having what their parents described as moderate disorder. Subgroups with significantly less-severe ADHD included girls and adolescents aged 15-17.
Boys, adolescents aged 15-17 years, and multiracial and non-Hispanic children all had significantly higher prevalence rates of current ADHD relative to their respective comparator subgroups. Gender, race, and ethnicity had no linkage with medication use, but medication treatment occurred less often in the 15- to 17-year-olds, said Ms. Danielson, a statistician on the Child Development Studies team of the CDC in Atlanta. Children aged 11-14 years had the widest medication use, 73%, while adolescents aged 15-17 had the lowest rate of medication, 56%, a statistically significant difference. Children aged 11-14 years with severe disease had a roughly 90% rate of medical treatment; teens aged 15-17 years with mild ADHD had the lowest medication rate, about 50%.
Children and teens with a concurrent diagnosis of disruptive behavior disorder had a statistically significant, 50% adjusted, relative increased rate of receiving medical treatment for their ADHD and also had a significantly higher prevalence of current, severe ADHD. More than 30% of children with the combination of current ADHD and disruptive behavior disorder had severe ADHD.
Ms. Danielson said that she had no disclosures.