To the Editor: In their commentary, published in the January 2010 issue of the Journal, Christian Kieling, M.D., et al. (1) presented the rationale for a DSM—5 proposal to increase the required age at onset for attention deficit hyperactivity disorder (ADHD) from age 7 years to 12 years. Unfortunately, the commentary did not include a risk/benefit analysis. The authors focus only on the benefit of reducing false negatives and ignore the considerable risk that eliminating this age of onset gatekeeper will result in a flood of new false positives for a diagnosis that may already be quite overinclusive.