[*] Read at the sixth annual meeting of the American Psychopathological Association, May 5, 1915, New York City. JOHN T. MACCURDY, M. D. Psychiatric Institute, Ward's Island and WALTER L. TREADWAY, M. D. Assistant Surgeon, U. S. Public Health Service MOST psychiatrists state or tacitly assume that dementia praecox is a disease of a steadily progressive nature, where the first symptom of dementia is a signal for relentless degradation of the patient's mental capacity except in the sphere of the more mechanical, intellectual functions. Yet the experience of every institutional physician denies the universality of this deterioration, and the statistics in any good text book demonstrate that many cases are "chronic" rather than "deteriorating." Woodman[1] has made a careful study of 144 such chronic cases, and shows what a surprisingly large proportion of these develop a good adaptation to the artificial environment of the institution. So far as we know, however, no one has attempted to formulate any definite features of onset which could be taken as a guide in determining the gravity of the mental derangement. In fact Bleuler states categorically that "up to the present no correlation has been discovered between the symptoms of onset and the gravity of the outcome." Kraepelin has split off from dementia praecox a separate psychosis--Paraphrenia systematica--which he timidly defends as a clinical entity apparently because the course is a long one and the deterioration less marked than in dementia praecox. But he gives us no concise prognostic data; in fact one feels on reading his paper that the diagnosis must be made post hoc. This problem is manifestly of equal importance from the social and the scientific standpoint: until we can predict the outcome our treatment must be empiric and palliative; we confess ourselves ignorant of the disease process if we cannot make a prognosis. [1] R. C. Woodman, N. Y. State Hospital Bulletin, Vol. II, No. 2, 1909.