[The problem of "middle cases". Psychopathologic and nosographic evaluation].

: A group of 246 psychotic patients diagnosed on the basis of DSM III R was compared to standard parameters in order to define the so-called "middle cases". A group of 12 patients who matched these parameters was thus obtained independently of the initial diagnosis. This group was then compared with two other groups of similar sizes made up of schizophrenic patients and patients suffering from major depressive disorders respectively; neither of the latter groups corresponded to the above mentioned standard parameters. This comparison revealed a substantial equi-distance between the three groups, thus confirming the inadequacy of a method of classification into categories when applied to such a complex and articulated field as psychosis.