Every time I turn around, it seems someone else is being diagnosed with attention-deficit hyperactivity disorder (ADHD). Are too many people being labeled with this diagnosis?
—Felix N. Chien, DO, Newport Beach, Calif.

It is difficult to answer the question of whether the incidence and prevalence of ADHD are increasing or whether more cases are being recognized. Reported estimates of ADHD prevalence run between 2% and 18%. This wide range reflects the lack of reliable epidemiologic data. For example, since ADHD is comorbid with many conditions (such as anxiety disorders) and because the diagnosis rests to a large degree on reports from parents and teachers, defining a “case” for epidemiologic surveys is difficult. Although the CDC’s 2003-2004 National Survey of Children’s Health study found ADHD in 7.8% of children aged 4-17 years (N = 79,264), longitudinal data showing trends in the diagnosis of ADHD are not available at this time. All that being said, more and more individuals are being treated for ADHD. One study reported that from 1987 to 1997, the rate of outpatient treatment for ADHD increased from 0.9 to 3.4 per 100 children. Comparable increases in prescription of ADHD medications to adults are also reported. 

Does this increase in treatment reflect overdiagnosis or increased recognition of the disorder? Although hyperactivity was recognized in children more than 100 years ago and the first report of stimulant use for hyperactivity symptoms appeared in 1937, the first diagnostic criteria for ADHD did not appear until 1980. Since then, recognition of ADHD symptoms has increased, both in children and adults. Given that the prevalence of ADHD in children seems to be around 10% and approximately 5% of children are currently being prescribed medication for this disorder, the increase in prescribing rates is consistent with better recognition of ADHD. Symptoms of learning disorders in children are often treated with stimulant medication. This may also partially account for the apparent increase in cases of ADHD.
—David Brody, MD, physician in charge of Psychiatric Outpatient Services, and Michael Serby, MD, associate chairman, Department of Psychiatry, Beth Israel Medical Center, New York City (119-23)