ABSTRACT
Kraepelin’s dichotomy of endogenous psychoses (1) into manic-depressive insanity and dementia praecox introduced, without doubt, a certain order into the chaos that had previously reigned in the classification of mental illnesses. Psychoses with a favorable prognosis were assigned to the group of manic-depressive disorders while those with an unfavorable prognosis were termed dementia praecox. This dichotomy was, however, confronted with the problem of ‘‘atypical psychoses’’ that concerned the classification of psychoses, which could be assigned neither to dementia praecox nor to manic-depressive insanity due to their ‘‘atypical’’ symptomatology. Furthermore, it was often impossible to determine the long-term prognosis of a psychosis from its momentary clinical picture, and it was found that psychoses resembling each other in the initial stages could either remit or result in more or less states of mental deficiency. Eugen Bleuler (2), therefore, replaced Kraepelin’s concept of dementia praecox by his concept of a group of ‘‘schizophrenias,’’ because ‘‘many diseases that could not be distinguished in their psychopathological appearance from psychoses leading to ‘‘imbecility’’ have a good prognosis, as does manic-depressive insanity. A term needed to be devised that would link together the disease forms with like symptomatology, even though some of them end in recovery, others in mental deficiency, and yet others in imbecility’’ (p. 47).
