Alteration of event related potentials in siblings discordant for schizophrenia

This study was aimed at confirming that auditory event related potential (E RP) abnormalities are indicators of vulnerability to schizophrenia. Auditor y ERP performances were assessed at Fz, Ct, and Pt, with an oddball paradig m, in 21 clinically stable patients with schizophrenia, 21 of their healthy biological full siblings and 21 control subjects. The evoked response did not differ between the three groups on N200 waves. Compared to controls, pa tients with schizophrenia exhibited reduced amplitudes of N100 and P300, an d prolonged latency of P300, while their siblings showed prolonged latency of P200 and P300. Among the patients with schizophrenia, ERP abnormalities did not correlate with age, clinical state, duration of illness or antipsyc hotic treatments. Although other conditions also accounted for alterations of the same type, ERP abnormalities may represent a neurobiological marker of the genetic vulnerability to schizophrenia, independent of phenotypic ex pression. (C) 2000 Elsevier Science B.V. All rights reserved.