BIZARRE DELUSIONS AND FIRST-RANK SYMPTOMS IN A FIRST-ADMISSION SAMPLE- A PRELIMINARY-ANALYSIS OF PREVALENCE AND CORRELATES

This report examines the prevalence and correlates of bizarre delusion s and Schneider's first-rank symptoms (FRS) in a first-admission sampl e with psychosis. A total of 196 patients were assessed with the Struc tured Clinical Interview for DSM-III-R (SCID) and given a consensus di agnosis. Project psychiatrists blind to the consensus diagnoses coded each delusion and hallucination in the sample for both FRS and DSM-III -R bizarreness. Interrater reliability of bizarreness was lower than t hat of FRS (kappa = .681 v 861). The majority of symptoms (72%) were n either bizarre nor FRS, and of the remainder, bizarre delusions that w ere not also FRS were extremely uncommon, The prevalence of FRS was 70 % in schizophrenia, 29% in psychotic bipolar disorder, and 18% in psyc hotic depression. For seven schizophrenic patients (7.45%), diagnosis of that disorder depended on the presence of a DSM-III-R bizarre delus ion to meet criteria. There was a trend for FRS to be associated with poorer prognostic features in the schizophrenic sample. We concluded t hat although the constructs of bizarre delusions and FRS overlap, FRS were a more important feature in schizophrenia than bizarreness. The r arity of bizarre delusions that were not FRS, combined with the lower reliability of their assessment as compared with that of FRS, raises q uestions about the continued emphasis on this phenomenon in the defini tion of schizophrenia. Copyright (C) 1995 by W.B. Saunders Company