Dr. Cynthia L. Leibson and colleagues examined the use and costs of healthcare services for a single cohort of children born in Rochester, Minnesota, between 1976 and 1982. The cohort included 4119 subjects who were followed through 1995, including 309 youths with a diagnosis of ADHD.

Children and youths with ADHD were significantly more likely than others to have multiple diagnoses, including asthma and major injuries, the researchers found. They were also more likely to have a record of inpatient, outpatient or emergency department admissions for any reason.

In an interview with Reuters Health, Dr. Leibson said that the nature of the association between ADHD and other health conditions remains unclear. She pointed out that the ADHD patients' increased contact with the medical system increased the likelihood that a condition would be uncovered or diagnosed.

Medical services for individuals with ADHD cost more than twice as much as services used by non-ADHD youth, with the difference particularly great for physician-billed services, the investigators report in the January 3rd issue of The Journal of the American Medical Association.

During 9 years of follow-up, the median medical cost for children and youths with ADHD was $4306 compared with only $1944 for individuals without a diagnosis of ADHD. This difference was independent of the gender or age of the individuals studied, the authors note.

The findings have several important implications for patients, parents, physicians, policymakers and third-party payors, Dr. Leibson said. For instance, "one implication of our finding that young persons with ADHD were more likely to be diagnosed with injuries and adverse events might be that affected individuals and their caregivers - parents and teachers - should exercise caution and be alert in risky situations," she explained.