Visual event-related potentials in first-episode psychotic patients and their relatives

We conducted a comprehensive examination of the sensory visual event- related potential (ERP) of psychiatric patients and their relatives using a methodology that improves upon those used previously by other investigators. One hundred thirty-five patients at the onset of their first psychotic episode, 146 first-degree relatives of these patients, and 113 normal controls were exposed to light flashes of four different intensities while their ERPs were recorded from three central scalp sites. For most analyses, various ERP amplitude measures did not discriminate the different psychiatric groups or their relatives either from one another or from the normal controls. These findings indicate that patients with schizophrenia, schizophreniform disorder, and affective disorder at the early stage of their illnesses do not display significant deficits in the processing and regulation of simple sensory visual stimulation.