AbstractObjectiveTo investigate the clinical characteristics of event‐related potential P300 in elderly schizophrenics with different levels of violence and the risk factors of severe violence.MethodsA total of 138 elderly schizophrenic patients from January 2020 to December 2021 in the First Hospital of Hebei Medical University were enrolled in this retrospective analysis. Based on the violence risk assessment, 61, 102, and 145 patients were divided into high‐risk, medium‐risk, and low‐risk groups, respectively. Clinical characteristics, P300 latency, and P300 amplitude were compared among the three groups followed by a logistic regression analysis of elderly schizophrenics with severe violence.ResultsThe latency of P300 in the high‐risk group was higher than that in the low‐risk group (p< .05). The P300 amplitude of patients in the high‐risk group was significantly lower than that in the low‐risk group (p< .05). Univariate logistic regression analysis showed that previous history of violence, delusion of persecution, P300 latency, and amplitude were independent influencing factors of severe violence in elderly schizophrenics (odds ratio [OR]: 0.022, 95% confidence interval [CI]: 0.007–0.067,p< .001; OR: 0.118, 95% CI: 0.043–1.763,p= .037; OR: 1.289, 95% CI: 1.142–1.673,p< .001; and OR: 0.049, 95% CI: 0.021–0.067,p< 0.001, respectively). After adjusting gender, age, and other confounding factors, multivariate logistic regression analysis showed that delusion of persecution, P300 latency, and P300 amplitude were associated with severe violence in elderly schizophrenics (OR: 2.211, 95% CI: 0.061–4.067,p< .001; OR: 2.006, 95% CI: 1.421–2.721,p= .017; and OR: 0.067, 95% CI: 0.037–0.276;p< .001; respectively).ConclusionThe latency and amplitude of P300 can be used as effective neuroelectrophysiological indicators to evaluate the violence level of elderly schizophrenics. Delusion of persecution, P300 latency, and P300 amplitude were independent influencing factors of severe violence in elderly schizophrenics.