[Event-related potentials P₃₀₀ with memory function and psychopathology in first-episode paranoid schizophrenia].

Objective: To investigate the variability of event-related potentials P(300) and the relationship with memory function/psychopathology in patients with first-episode paranoid schizophrenia.

Methods: Thirty patients with first-episode paranoid schizophrenia (patient group) and twenty health subjects (control group) were enrolled in the study. The auditory event-related potentials P₃₀₀ at the scalp electrodes Cz, Pz and Wechsler Memory Scale (WMS) were examined in both groups, Positive And Negative Syndrome Scale (PANSS) was evaluated in patient group.

Results: In comparison with control group, patients had longer latency of P₃₀₀ [(390.6 ± 47.6)ms at Cz and (393.3 ± 50.1)ms at Pz] (P<0.01), lower amplitude of P₃₀₀ [(7.7 ± 3.4) μV at Cz and (8.5 ± 3.9)μV at Pz] (P<0.05-0.01). The memory quotient (88.1 ± 10.0) scores and short-term memory, immediate memory in patient group were damaged significantly (P<0.05-0.01). In patient group, the latency of P300 was correlated positively with PANSS scores and negatively with WMS scores (P<0.05-0.01).

Conclusion: First-episode paranoid schizophrenia has memory deficit, which can be evaluated comprehensively by P₃₀₀ and WMS. The longer latency of P₃₀₀ might be associated with the increased severity of first-episode paranoid schizophrenia.