Three major roots are reflected in all definitions: a) the
Kraepelinian emphasis on avolition, chronicity and poor outcome
(Kraepelin, 1971); b) incorporation of the Bleulerian viewthat dissociative
pathology is primary and fundamental and accent on negative
symptoms (Bleuler, 1950); and c) the Schneiderian stress on reality
distortion or positive symptoms (Schneider, 1959).