[The concept of psychosis and psychotic qualities].

The term "psychosis," first used by Canstatt and then by von Feuchtersleben, originally meant "psychic neurosis," one of several forms of one disease group. The term was taken up by Flemming and introduced among other typical indications such as psychic disturbance, psychic disease, mind disease, and madness around 1875 in the German-speaking world."Psychosis" was understood from the beginning as a cerebral pathology which found its expression in psychic symptomatology. The broadest interpretation of the concept of psychosis prior to the turn of the nineteenth to the twentieth centuries has today been reduced to the modern differentiations of psychopathologies and neuroses. Since then, no consensus has been reached on the extent of the concept of psychosis.We have remained at the "persistent unclarity" described by H. Kindt. Contemporary diagnostic systems have done without the concept of psychosis. The indication "psychotic" which has taken its place and is based primarily on characteristically schizophrenic phenomena is also unclear. Independently of the unsolved problem of differentiation, there remains the question of psychotic qualities which are understandable on biologic and psychopathologic levels at the same time and which combine biologic, interpretative, and descriptive elements, uniting them in the field of biologic and clinical psychiatry.