Emil Kraepelin, answered from the texts and cited to the page.
The confused surface of psychiatric symptoms resolves, when patients are followed over time, into a small number of natural disease forms — above all the deteriorating course of dementia praecox and the recurring, recovering course of manic-depressive insanity.12 Symptoms cross the boundaries; COURSE and OUTCOME do not, and it is by these that the true entities are known.3
Perhaps also the very desirable clearing up of the doctrine of the "late catatonias" will bring us a further increase of forms. On the other hand again perhaps some of the smaller groups will in course of time be got rid of; I think first of this possibility namely for the cases with confusion of speech and those with 2l periodic course.Dementia Praecox and Paraphrenia
The extraordinary enlargement of our conception of the disease is subjected on the other hand also to noteworthy limitations. It must first be remembered that only a part of the cases formerly called " mania " and " melancholia " have been included in manic-depressive insanity. A con- siderable number of cases, which formerly were taken ^ Friedmann, Monatsschr. f. Psychiatric, xv. 301. ^ Mugdan, Zeitschr. f. d. ges.Manic-Depressive Insanity and Paranoia
DELIMITATION. Whether dementia praccox in the extent here delimited represents one uniform disease^ cannot be decided at present with certainty.Dementia Praecox and Paraphrenia
That the dichotomy is the right FIRST cut of the psychoses I hold; that its boundary is perfectly sharp I came in my last work (1920) to doubt myself, writing that the two great groups shade into one another at their edges. The entities are real forms, not perfectly walled kingdoms.