WEDNESDAY, Nov. 10 (HealthDay News) -- The number of U.S. children with attention-deficit/hyperactivity disorder (ADHD) jumped nearly 22 percent in a recent four-year period, meaning nearly one in every 10 kids is now diagnosed with the disorder, U.S. health officials report.
"Based on our parent surveys, there has been an increase in parent-reported ADHD diagnosis among their children," said lead author Susanna Visser of the U.S Centers for Disease Control and Prevention.
"This increase was from 7.8 percent in 2003 to 9.5 percent in 2007," she said. "When we project that to the American population, that means that a million more children were diagnosed with ADHD in 2007 as compared to 2003. That's a substantial increase in four years."
About 5.4 million children have ADHD in the United States, according to their parents, and 2.7 million take medication for the condition, the CDC survey of 4- to 17-year-olds found.
"There are probably more children out there who have not received a diagnosis and we can't determine how many more children there are based on these data," added Visser, lead epidemiologist of the child development studies team at the CDC's National Center on Birth Defects and Developmental Disabilities.
ADHD, a neurobehavioral disorder, is characterized by levels of inattention and activity that are developmentally inappropriate. The condition can persist into adulthood.
Among older teens, the rate of ADHD soared 42 percent, the researchers found. This suggests that health care providers may be managing a larger and different population of children than they were four years ago.
"We don't know as well how to manage ADHD among older teens," Visser said. "Regardless of why we are seeing this, the end result is that health care providers are going to modify their care approach to consider the needs of older teens," she said.
The 53 percent increase in ADHD diagnosis since 2003 among Hispanics means providers are going to have to be sensitive to the needs of this group as well, Visser added.
Much of the increase may be driven by better screening programs and more awareness and diagnosis, Visser said.
The report is published in the Nov. 12 issue of the CDC's Morbidity and Mortality Weekly Report.
One expert isn't surprised by the numbers.
"I believe the findings are generally accurate and consistent with most research in detailing the rapid and rather disconcerting rise in the diagnosis of ADHD in U.S. children," said John D. Ranseen, an associate professor of psychiatry at the University of Kentucky College of Medicine.
The rapid rise in diagnosis, which is not necessarily equivalent to a rise in the actual condition, must be due in part to cultural factors -- a willingness to label certain symptoms as indicating ADHD, increased cultural acceptance of doing so and increased dissemination of information labeling ADHD as a "condition," he said.
Other, more vague, cultural factors may also play a role, Ranseen pointed out.
"For instance, increased stress to complete as much schooling as possible within a lousy economy," he noted.
"Another very uncomfortable issue is the role of pharmacological companies in all of this since it is very much in their interest to increase the diagnosis and treatment of this condition. The last thing they have any interest in seeing is a drop in the diagnosis and treatment," Ranseen said.
"One would hope that such findings might give the mental health field pause to wonder and worry about why we are seeing increases in virtually all psychiatric conditions -- autism, depression, ADHD, bipolar in children -- for instance, what does this say about our society?" Ranseen added.
But another ADHD expert, Dr. Jeffrey Brosco, professor of pediatrics at the University of Miami Miller School of Medicine, said parent-reported studies make it hard to ascertain true figures.
Whether the number of children with ADHD is actually increasing or whether the increase is a product of increased awareness isn't known, Brosco said.
"I don't know and I don't think anyone can really tell you based on this study," he said. "There is no doubt that over the last 30 to 40 years we have become much more sensitive to behavioral differences," Brosco said. "Whether there is truly a change -- whether kids in the 1970s are really different from kids in the '90s or the 2000s -- there's not any way to tell that."
For more information on ADHD, visit the U.S. National Institute of Mental Health.