Schizophrenic first-rank symptoms in organic mental disorders.

The frequency of schizophrenic first-rank symptoms (FRS) were investigated in 1698 patients with an organic mental disorder (OMD) according to Schneider's and DSM-III criteria: 7% of the patients with OMD had FRS, compared with 47% of schizophrenic patients. However, the frequency of FRS depends on the state of consciousness and on the aetiology of the OMD: 20% of the patients with clear consciousness had FRS, but only 1.5% of those with clouded consciousness. In cases of some aetiologically defined groups of OMD, such as post-ictal epileptic psychoses or alcoholic hallucinosis, the frequency of FRS is similar to that in cases of schizophrenia. FRS appear to be psychotic reaction patterns whose substrate-related basis extends across the whole spectrum of endogenous and exogenous psychoses.