Relations between the classification of endogenous psychoses by Leonhard, the doctrine of pathoclisis by Vogt and the neurological conception of system diseases.

On the basis of 30 years of cowork with Leonhard it is attempted to enlighten the theoretical background of his classification of endogenous psychoses. Inspired by the conceptions of Wernicke and Kleist he explained the differentiation of symptomatology by the model of system diseases applying this in completing and improving the psychopathological classification. His ideas about the origin of a differentiated vulnerability of brain structures are very similar to the doctrine of pathoclisis of Vogt, although Leonhard did not use this term.