The results reported in the article by Rappley et al1 in the June 1995 issue of the Archives are misleading regarding the extent of attention-deficit hyperactive disorder (ADHD) in Michigan. They underestimate what appears to be a major "epidemic" and/or large-scale overdiagnosing of ADHD.
The method used to determine ADHD is based on an analysis of only 2 months of prescribing methylphenidate hydrochloride. As indicated in a literature review, Sherman and Hertzig2 found that more than half of all methylphenidate prescriptions written during 1986 in New York were for 1 prescription per child per year. If Michigan's prescribing was similar to New York's, and 50% of the patients received only 1 methylphenidate prescription per year, the authors could have missed 42% of the patients diagnosed and treated for ADHD during 1 year from this factor alone, besides missing other patients receiving more than 1 prescription in 1 year