Event-related potentials and genetic risk for schizophrenia

Background: Event-related potentials (ERPs) during an auditory oddball task were investigated in patients with schizophrenia and in their healthy sibl ings to explore the question of whether abnormalities of two-dimensional to pographic scalp-distribution of P300 amplitude and latency relate to geneti c risk for schizophrenia. We also examined the P50, N100, and P200-waves, e licited during the same task. Methods: We investigated 42 schizophrenic patients, 62 of their healthy sib lings, and 34 unrelated normal control subjects with a standard auditory od dball paradigm and 16 electroencephalogram electrodes. Amplitudes and laten cies of the ERPs P50, N100, P200, and P300 were topographically analyzed. Results: In the patients, P300 amplitude was significantly decreased in the range of 54%-58% over the left parietotemporal area. Siblings did not show decreased P300 amplitudes when compared with normal subjects. P300 latenci es were unchanged in both groups. No significant group differences were obs erved for the other event-related potentials. Conclusions: In line with previous studies, the P300 amplitude in schizophr enic patients was decreased over the left temporoparietal area; however, we found no evidence for a genetic trait effect in the event-related potentia l abnormality. Possible reasons for these largely negative findings are dis cussed. Biol Psychiatry 2001; 50:407-417 (C) 2001 Society of Biological Psy chiatry.