What the public and even experts suspected is now supported by representative data collected by researchers at Ruhr-Universität Bochum (RUB) and University of Basel: ADHD, attention deficit hyperactivity disorder, has been over-diagnosed. New studies show that child and adolescent psychotherapists and psychiatrists have tended to give a diagnosis based on heuristics and unclear rules of thumb rather than adhering to recognized diagnostic criteria. Boys in particular are substantially more often misdiagnosed compared to girls. 

The researchers surveyed altogether 1,000 child and adolescent psychotherapists and psychiatrists across Germany. 473 participated in the study. They received one of four available case vignettes, and were asked to give a diagnoses and a recommendation for therapy. In three out of the four case vignettes, the described symptoms and circumstances did not fulfill ADHD criteria. Only one of the cases fulfilled ADHD criteria based strictly on the valid diagnostic criteria. In addition, the gender of the child was included as a variable resulting in eight different case vignettes. As the result, when comparing two identical cases with a different gender, the difference was clear: Leon has ADHD but Lea does not. 

Many child and adolescent psychotherapists and psychiatrists seem to proceed heuristically and base their decisions on prototypical symptoms - namely that the prototype is male and shows symptoms such as motoric restlessness, lack of concentration and impulsiveness. In connection with the gender of the patient, these symptoms lead to different diagnoses. A boy with such symptoms, even he does not fulfill the complete set of diagnostic criteria, will receive a diagnosis for ADHD, whereas a girl will not. Also the therapist's gender plays a role in the diagnostic: male therapists give substantially more frequently a diagnosis for ADHD than their female counterparts.

As media attention increased, ADHD diagnoses also became inflationary. Between 1989 and 2001, the number of diagnoses in German clinical practice increased by 381 percent. The costs for ADHD medication, such as for the performance-enhancer Methylphenidate, have increased 9 times between 1993 and 2003. The German health insurance company, Techniker, reports an increase of 30 percent in Methylphenidate prescriptions for its clients between the ages of 6 and 18. Similarly, the daily dosage has increased by 10 percent on average.

Where was the research to justify all that?  No where.  The diagnoses, and then increased diagnoses, were the evidence.

It's not like the alarming statistics were not there, but even then there was a remarkable lack of research in the diagnosis of ADHD. "In spite of the strong public interest, only very few empirical studies have addressed this issue", study authors Prof. Schneider and Dr. Bruchmüller point out.

While in the 70s and 80s a "certain upswing" of studies on the frequency and reasons for misdiagnoses could be observed, current research hardly examines the phenomena. The current study shows that in order to avoid a misdiagnosis of ADHD and premature treatment, it is crucial for therapists not to rely on their intuition, instead to strictly adhere to defined, established diagnostic criteria. This is best possible with the help of standardized diagnostic instruments, such as diagnostic interviews.

Studies:

K. Bruchmüller, S. Schneider: Fehldiagnose Aufmerksamkeits- und Hyperaktivitätssyndrom? Empirische Befunde zur Frage der Überdiagnostizierung. Psychotherapeut 2012, DOI: 10.1007/s00278-011-0883-7

K. Bruchmüller, J. Margraf, S. Schneider: Is ADHD Diagnosed in Accord With Diagnostic Criteria? Overdiagnosis and Influence of Client Gender on Diagnosis. Journal of Consulting and Clinical Psychology 2012, DOI: 10.1037/a0026582