It is unfortunate that the most disabling and costly group of disorders, the psychiatric diseases, is so poorly defined and investigated. Nosologic conceptualization and diagnostic categorization of even hospitalized patients are painfully disparate and disorganized.1 Estimates of prevalence and severity vary all the way up to three-quarters of the population ill with one-quarter severely disturbed. Indeed, some of the psychoanalytic writers imply that all individuals have some symptoms, and that psychiatric disorder consists of a continuum of psychologic disturbance. This has resulted in a nihilistic consideration of psychiatric diagnosis with explicit statements that diagnoses are unimportant or indeed harmful to the therapeutic process, thereby precluding effective epidemiologic interest and research. Nothing is more destructive to scientific investigation since classification is fundamental to science and must influence therapeutic management as well.
Some of the more recent statements in the lay