The largest study to determine the effectiveness of various treatments for attention deficit hyperactivity disorder shows that stimulant drugs produce the most benefits, but that most children with the disorder are undertreated with the drugs.
The study found that medication is more effective than behavioral therapy. It is expected to fuel the controversy surrounding drug treatment for ADHD, especially among critics who argue children are being overmedicated.
Compared to the average child with ADHD treated in the community, those who receive the most commonly prescribed stimulant--Ritalin-- three times a day, instead of two, and who receive higher doses have a much higher rate of normalization, said Benjamin Lahey, a professor of psychiatry and chief of psychology at the University of Chicago.
"Ritalin is not like penicillin, where you give one dose for everybody," said Lahey, who helped select the children to participate in the federal study. "You have to tailor Ritalin to the individual child, and you have to keep getting feedback from the parents and teachers on how well it is working and what side effects they're seeing."
Typically, physicians see a child with ADHD only once or twice a year, prescribe lower doses of Ritalin and seldom adjust the dosage, Lahey said.
"Probably, the majority of children with ADHD are not receiving Ritalin in this systematic and aggressive way that seems to be the most effective," he said.
Experts estimate that ADHD affects 3 to 5 percent of school-age children. On average, every classroom has one or more children with symptoms of the disorder, characterized by an inability to sustain attention and concentration, developmentally inappropriate levels of activity, distractibility and impulsive behavior.
There are no accurate figures on the number of children taking Ritalin on a regular basis, but it is estimated that there are between 1 million and 2 million.
The ongoing study, sponsored by the National Institutes of Mental Health, is the first major clinical trial to look at childhood mental illness and the largest NIMH clinical trial to date.
The study involves 600 elementary schoolchildren, aged 7 to 9, who have been followed for 14 months at six centers across the country. Researchers plan to follow the children into adulthood to closely monitor the long-term effects of stimulant medication. The results are to appear in the December issue of the American Medical Association's Archives of General Psychiatry.
The study compared the effectiveness of stimulant medication alone, behavioral therapy alone, a mix of stimulant medication and behavorial therapy, and typical care in the community, the kind most ADHD children experience.
"We found that, when the best behavioral-management treatment and medication treatments are pitted head to head, medical treatment is a hands-down winner," said Dr. Peter Jensen of the NIMH, who headed the study.
In some situations where a child suffers from anxiety as well as ADHD, medication along with behavioral therapy produces the greatest success, he said.
Combined therapy normalized about two-thirds of the children to the point they could not be distinguished from non-ADHD children, Jensen said. All children tended to improve over the course of the study, but they differed in the relative amount of improvement.
Medication alone normalized about half of the children, therapy alone worked for about one-third and average care in the community had the poorest results, improving symptoms for only about one-fourth of the children, Jensen said.
Drug use to treat children with behavioral problems has drawn fire from educators and others. The Colorado State Board of Education last month passed a non-binding resolution urging teachers to use academic solutions to resolve problems with behavior, attention and learning. The resolution cited incidents in which drugs are prescribed for behavior that is better addressed by academic discipline.
Jensen said that, in addition to the substantial benefits for ADHD children from stimulant medications, fewer of those on Ritalin developed such problems as conduct disorder, oppositional behavior, anxiety and depression, which often affect children with ADHD.
"There's reason to think that effective treatment makes a difference," he said. "What is not predictable is who is going to improve from drug therapy and whether drug usage can gradually be tapered off."