Researchers seek objective way to diagnose attention disorder

By Cathy Seigerman

A new study conducted at the U.Va. Health System and Sweet Briar College is the first in the United States to measure physical brain changes that could confirm a child's having attention deficit and hyperactivity disorder (ADHD), one of the most common behavioral problems in children.

"Unlike diabetes or hypertension, there is currently no way to measure ADHD objectively," said Dr. Daniel Cox, director of U. Va.'s Behavioral Medicine Center and principal investigator of the study.

Doctors currently rely on subjective observations to diagnose ADHD, he said. "As a result, medications for ADHD, such as Ritalin, may be overprescribed for children who do not actually have the condition."

Another study, recently published in the Journal of the American Medical Association, reported a rapid increase in prescriptions of Ritalin for children age 2 to 4 between 1991 and 1995.

"Individuals with ADHD are thought to have more slow wave and less fast wave activity in the brain. The stimulant Ritalin speeds up the brain activity to match that of non-ADHD individuals... theoretically," Cox said.

Three to 5 percent of American children exhibit ADHD symptoms, according to the Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association. Of all child referrals to mental health services, one-third to one-half are due to ADHD, Cox said. A recent survey by the Center for Pediatric Research found that in the Virginia cities of Portsmouth and Virginia Beach, 10 percent of public school children in grades two through five were taking ADHD medication.

Cox and researchers from Sweet Briar developed a unique brain wave measurement model based on research at NASA's Langley Porter laboratories to measure the brain waves of fighter jet pilots. The test senses changes that occur when subjects shift their attention from one task to another.

In preliminary studies with children 9 to 11 years old, "we have seen that the brain wave activity of a non-ADHD child is stable when the child moves his attention from one task to another. By contrast, the brain waves of children with ADHD are very chaotic when they are shifting to another task," Cox said. The current study, supported with a grant from the Virginia Commonwealth Health Research Board, includes 80 children and will continue for four months. Those with ADHD must cease taking any medication for at least 24 hours before testing.

Studying the EEG readings was a slow-going, tedious task until mathematician Boris Kovatchev, an assistant professor on the research team, developed software to analyze the data. That's made all the difference, Cox noted.

Coming up with an objective diagnostic tool that firmly documents that ADHD changes brain waves could also help with prescribing medications, especially in making the appropriate dosage, which is hard to determine, Cox said.

The researchers are looking at this age group rather than younger children because the brain has matured by the age of 9, and the alpha brain waves are stable. If their results are confirmed, they plan to analyze other groups, such as younger children, or children with ADHD who are taking Ritalin compared with those who are not, he added.

Those families interested in participating in the study, including children with or without ADHD, should call 924-8655.