Report highlights diagnostic and treatment uncertainties in ADHD

Significant local and international variations in the diagnosis and treatment of attention deficit-hyperactivity disorder (ADHD) stem at least in part from a "zone of ambiguity"--different interpretations of what is normal behavior and what level of impairment is required for a psychiatric diagnosis.

Furthermore, the long-term effectiveness of different treatments is unclear. These are among the conclusions of a new report by Hastings Center scholars published online in the current issue of Child and Adolescent Psychiatry and Mental Health.

The report grew out of a two-day interdisciplinary workshop in which psychologists, psychiatrists, pediatricians, sociologists, anthropologists, and others discussed controversies in the diagnosis and treatment of ADHD. The workshop was the second in a series of five workshops being convened by The Hastings Center to explore controversies in the use of psychotropic medications in children. The project is funded by the National Institute of Mental Health.

Because the ADHD diagnosis is based on interpretation of a variety of symptoms, which exist on a continuum from mild to severe, and because a child's level of impairment depends on a variety of circumstances, there is an inevitable `zone of ambiguity,' which reasonable people will interpret differently.

Other variables also help explain variations in diagnosis and treatment rates. Different countries use slightly different diagnostic systems-American clinicians use the Diagnostic and Statistical Manual IV whereas European clinicians use the 10th edition of the World Health Organization's International Classification of Diseases. "In short, the DSM system casts a wider net than does the ICD, which is one reason why ADHD diagnosis is most common in the U.S.," write Hastings Center scholars Erik Parens and Josephine Johnston.

Cultural differences in parenting styles and school environment may also influence rates of diagnosis and treatment. "Different cultures and environments will be more or less tolerant of active, distractible children, and will be more or less prone to see impairment from those behaviors" the authors write.

Particularly provocative is the authors' observation that "the facts surrounding the most effective treatment of ADHD are complicated and incomplete." They cite an influential federally funded study comparing stimulant medication with behavioral therapy and combination treatment, which was widely interpreted as finding medication superior in reducing ADHD symptoms, even though a follow-up study found all three treatment options similarly effective.

Furthermore, research has not established that medication alone leads to improved academic improvement over the long term. Data presented by two of the workshop participants also suggest that combined medication and behavioral interventions can make it possible to use lower drug doses. "One thing, however, is clear," according to the authors. "Parents, teachers, and physicians all deserve to know the state of the evidence."