COGNITIVE-FUNCTIONING AND ANHEDONIA IN SUBJECTS AT RISK FOR SCHIZOPHRENIA

This study investigated the performance of individuals with familiar l oading of schizophrenia (healthy siblings of schizophrenic inpatients) on three neuropsychological tasks assumed to require frontal lobe fun ctions: Trail Making Test (TMT), verbal fluency and Wisconsin Card Sor ting Test (WCST). Healthy siblings of schizophrenics differed in perfo rmance from healthy controls not only on the WCST, but also on the Tra il Making Test and the verbal fluency task. Furthermore, scores of phy sical anhedonia, assessed in a self-report rating scale (Chapman et al ., 1976) were also significantly higher in the high risk group than in the control sample. However, healthy siblings of schizophrenics did n ot differ from controls with regard to experiences of perceptual aberr ations, measured by the same method (Chapman et al., 1978). Neuropsych ological performance and elevated anhedonia scores in the high risk gr oup were interpreted under the conceptual framework of vulnerability m arkers: they were supposed to represent a trait shared by family membe rs of schizophrenic probands. Amongst the neuropsychological tests, th ere were significant correlations between the physical anhedonia score and WCST and Trail Making test performance in the group of healthy si blings of schizophrenics, but not in the control group.