To the Editor: Dr. Evans suggests that mental health professionals in the United States and United Kingdom favor diagnosing white children with ADHD and black children with conduct disorder. To support this assertion, he cites our recent finding of a higher rate of treatment of ADHD in white than black youth in the United States and a British epidemiological study that reported a statistically nonsignificant higher rate of conduct disorder in black than white children. The British study also found that across all ethnic groups, conduct disorders were highly comorbid with ADHD, with an odds ratio of 38.43 (95% confidence interval=26.87–54.96). However, bias in routine diagnostic practices cannot be established by analyzing patterns in community prevalence or treatment rates. Such diagnostic biases can be measured only by studying the behavior of mental health professionals in relation to a criterion standard.

The possibility of widespread ethnic bias in routine clinical diagnostic practice merits careful scientific study. Such research might involve comparisons of ethnically sensitive independent expert diagnostic assessments (1) with clinical diagnoses in routine care or sampling the diagnostic judgments of mental health professionals with standardized clinical patients or vignettes that systematically vary patient ethnicity (2). In the absence of such research, the politically charged speculation offered by Dr. Evans runs the risk of trivializing what may be an important issue in the delivery of child mental health services.