Georges Canguilhem and the diagnosis of personality disorder.

Psychiatric participation, actual and anticipated, in the detention of “sexually violent predators” in the United States and “dangerous severe personality disordered” people in the United Kingdom provokes controversy. Much of this controversy concerns the proper roles of doctors and other mental health professionals. And since existing and proposed legislation requires that a person have a mental disorder or mental abnormality before he can be detained, debate has focused also on criteria for diagnosing personality disorders and some paraphilias. As a diagnostic category, personality disorder has a long and controversial history. In the past 20 years, the debate has included disagreement about the degree to which an Axis II diagnosis is a valid indicator of mental disorder. Current psychiatric classifications adopt a descriptive approach and list as signs of personality disorder particular personality traits. But those traits are not restricted to the personality disordered. No criterion has been identified for which there is a “zone of rarity,” in terms of its statistical distribution in the population, between those who can be reliably diagnosed as personality disordered and those who cannot. Diagnoses elsewhere in psychiatry and medicine often derive validity from evidence of “dysfunction.” The concept of dysfunction, however, has proved difficult to apply consistently to personality disorders. A person’s performance in the activities of daily living, for instance, seems peripheral to whether he has a personality disorder.