Project Summary

Franz X. Vollenweider, M.D., FMH (Independent Investigator 2004) of Psychiatric University Hospital in Zurich/Zurich University, aims to study how certain deficits in early information processing, such as prepulse inhibition (PPI) and suppression of the P50 event-related potential, relate to cognitive functioning in people having their first episode of schizophrenia. Schizophrenia has been conceptualized as a disorder with deficits in early information processing that lead to difficulty in inhibiting or filtering of irrelevant internal and external stimuli. Such filtering deficits may render schizophrenia patients to become overloaded with excessive stimuli which in turn could lead to breakdown of cognitive functioning and difficulty in distinguishing of self and non-self. Accumulating evidence suggests that patients with schizophrenia spectrum disorder have deficits in variety of psychophysiologic paradigms designed to assess central inhibition, including prepulse inhibition (PPI) of the startle response and suppression of the P50 event-related potential. PPI-deficits have repeatedly been confirmed in chronic schizophrenia spectrum patients, their relatives and subjects with schizotypal personality disorder. Recently Dr. Vollenweider found PPI deficits in never-medicated first-episode schizophrenia patients. Similarly, deficits in P50 gating were reported in chronic schizophrenia spectrum and schizotypic personality disorder patients. Hence the PPI and P50 paradigm have been proposed to reflect vulnerability markers to identify subgroups of schizophrenia spectrum disorders in order to improve our understanding of the pathophysiology of this disorder and treatment strategies. However, although schizophrenia spectrum patients show both P50 and PPI deficits, virtually nothing is known about the interdependency of these two gating measures in unmedicated and incipient schizophrenia patients. The proposed study aims to correlate PPI and P50 relate to cognitive performance and psychopathology in first-episode schizophrenia and to identify the neuronal network involved in the modulation of PPI and P50 in schizophrenia. Also, the researchers will study how atypical antipsychotics influence PPI and P50 and whether these measures can describe distinct subtypes of schizophrenia.

Program Area: SCHIZOPHRENIA/PSYCHOTIC DISORDERS\Schizophrenia

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