title: New concepts in the diagnosis of psychiatric disorders.
abstract: The salient points in this paper include the following: (a) a description of categorical (typological) diagnosis, applicable to psychiatric as well as to medical illness; (b) description and discussion of the five steps necessary to validate clinically a categorical (typological) diagnosis; (c) a description of the currently primitive state of laboratory studies of functional disorders (e.g. schizophrenia, affective disorders, and other functional disorders); (d) a definition of various psychiatric illnesses and a description of the criteria necessary to qualify a symptom for describing them; and (e) the means and purposes of assessing diagnostic homogeneity or heterogeneity in psychiatric illnesses.
mesh_terms: D019411:Clinical Laboratory Techniques; D003863:Depression / Q000175:diagnosis; D003937:Diagnosis, Differential; D005190:Family; D005500:Follow-Up Studies; D006801:Humans; D007406:Interview, Psychological; D001523:Mental Disorders / Q000175:diagnosis*