Psychiatric nosology

Psychiatric nosology is the branch of medicine concerned with the classification and description of psychiatric disorders.

The standard system of classification now employed in much of clinical practice and research in the United States and throughout the world is the updated version of the early manual devised by the American Psychiatric Association and now published under the title Diagnostic and Statistical Manual of Mental Disorders (1952; 1968; 1980; 1987; 1994). The latest version, DSM-IV is said to be "fully compatible with… ICD-10" (American Psychiatric Association, 1994, p. xxi), which is the International Classification of Diseases and Related Health Problems published by the World Health Organization.

An important distinction should be made between Psychiatric nosology as promulgated in the various editions of DSM from 1952 on and what may be referred to as "Somatic nosology." The former is based almost exclusively on either descriptions of behavior as reported by various observers, such as parents, teachers, and medical personnel; or symptoms as reported by patients themselves. As such, they are quite subjective, not amenable to verification by third parties, and not readily transferable across chronologic and/or cultural barriers.

Somatic nosology, on the other hand, is based almost exclusively on the objective histologic and chemical abnormalities which are characteristic of various diseases and can be identified by appropriately trained pathologists. While not all pathologists will agree in all cases, the degree of uniformity allowed is orders of magnitude greater than that enabled by the constantly changing classification embraced by the DSM-# system.

See also:

 * Nosology
 * Diagnosis
 * Medical Classification
 * Diagnostic and Statistical Manual of Mental Disorders