In his accompanying article, Dr. Kinscherff has convincingly demonstrated why a categorical exclusion of personality disorders from the definition of “mental disease” in insanity defense adjudication is arbitrary, both conceptually and clinically. He explains his position in the context of a vignette involving a hypothetical defendant, Wilhelmina Sykes, charged with ramming her car into another car obstructing her path, causing serious injury to its driver. Dr. Kinscherff correctly points out that the determinative issue in applying the insanity defense in any case, including the hypothetical case involving Ms. Sykes, is whether the defendant experienced a legally relevant functional impairment at the time of the offense. In many states — and in the hypothetical jurisdiction in which Ms. Sykes is being prosecuted — the relevant functional impairments are those that could have affected her ability “to appreciate the wrongfulness of her conduct” or “to conform her conduct to the requirements of the law.