The Use of the Term `Undiagnosed Psychiatric Disorders'

¹ Associate Professor of Psychiatry, Washington University School of Medicine, 4940 Audubon Avenue, St. Louis, Missouri 63110, U.S.A.

There is abundant evidence for the importance of diagnostic classification in psychiatry. Such classification has been useful over the years as a basis for clinical and laboratory investigation and for treatment of patients. The physician should classify patients only according to syndromes which have been shown, through adequate clinical descriptions and longitudinal and family studies, to have characteristic symptom-pictures and courses over time. When a psychiatrically ill patient does not fit such an established diagnostic category it is most accurate to describe him as `undiagnosed'. More precise classification of some such patients will be possible at follow-up, if in the course of time the clinical picture has become typical of an established syndrome. Classification of other undiagnosed patients, however, must await either the development of more accurate and varied means of diagnosis than are currently available, or the indentification of additional psychiatric syndromes through systematic longitudinal and family studies.