PARANOID SCHIZOPHRENIA - NONSPECIFICITY OF NEUROPSYCHOLOGICAL VULNERABILITY MARKERS

During stages of remission, patients with paranoid schizophrenia seldo m show severe attentional or information-processing dysfunctions, exce pt in cases of long-term chronicity. The diagnostic specificity of fou r putative psychological vulnerability indicators of schizophrenia - t he Span of Apprehension, the degraded stimulus Continuous Performance Test (dsCPT), the degraded stimulus visual backward masking task and t he Wisconsin Card Sorting Test (WCST) - was examined in a group of pat ients with paranoid schizophrenia. Since no single test seems to ident ify all patients, the use of a combination of measures may be a useful strategy. Accordingly, the four tests were administered to 18 paranoi d schizophrenic patients, 18 depressed patients and 18 normal subjects . Paranoid schizophrenic patients could be distinguished from normal s ubjects primarily on the basis of their performance on the backward ma sking task and secondarily by the dsCPT and the WCST. Paranoid schizop hrenic and depressed patients could be differentiated to some extent b y their performance on an information-mask condition of the backward m asking task. Thus, of the four measures studied, only the degraded sti mulus backward masking appeared to be a specific indicator of paranoid schizophrenia. (C) 1997 Elsevier Science Ireland Ltd.