›› 2010, Vol. 30 ›› Issue (9): 1133-.doi: 10.3969/j.issn.1674-8115.2010.09.027

• Original article (Clinical research) • Previous Articles     Next Articles

Changes of event related potential component N400 in first episode schizophrenia before and after risperidone treatment

CHEN Xing-shi1, XU Yi-feng2, TANG Yun-xiang3, XIAO Ze-ping2, ZHANG Ming-dao1, WANG Ji-jun4, |LOU Fei-ying1, |CHEN Chong1   

  1. 1.Department of Electrophysiology, 2. Department of Psychiatry, Shanghai Mental Health Center, |Shanghai Jiaotong University School of Medicine, Shanghai 200030, China;3.Department of Psychology, The Second Military Medical University of PLA, Shanghai 200433, China;4.Department of Electronic Encephalography Source Imaging, Shanghai Mental Health Center, |Shanghai Jiaotong University School of Medicine, Shanghai 200030, China
  • Online:2010-09-25 Published:2010-09-27
  • Supported by:

    National Natural Science Foundation of China, 30770772, 30971046;National Basic Research Program of China, “973” program, 2010CB529605;National High Technology Research and Development Program of China, “863” program, 2008AA02Z412, 2007AA02Z420


Objective To explore the relationship between event related potential (ERP) component N400 changes and syndromes and treatment in first episode schizophrenia (FES), and investigate the mechanism of N400 changes. Methods Chinese sentences with matching (congruent) or mismatching (incongruent) ending words were used as stimuli, and ERP component N400 was recorded by Runjie WJ-1 ERP instrument (China) in 56 patients with FES (FES group) and 62 healthy controls (NC group). Psychiatric symptoms were assessed by Positive and Negative Syndrome Scale (PANSS). Patients in FES group were treated by single antipsychotic drug risperidone, and N400 was monitored after treatment for 3 months and 12 months in both groups. Results Compared with NC group, N400 latencies in Cz, Pz and Fz prolonged, and N400 amplitudes decreased in FES group. In Cz of FES group, the prolonged N400 latency was positively correlated to the general psychopathological score in PANSS (r=0.319, P<0.05), and the decreased N400 amplitude was negatively correlated to the positive score and total score of PANSS (r=-0.425,P<0.01;r=-0.348,P<0.05). Compared with those before treatment, no significant changes were found in PANSS score, N400 latencies and N400 amplitudes in FES group after treatment for 3 months (P>0.05). Twelve months after treatment, psychiatric symptoms in FES group relieved, and the total PANSS score decreased to 29.5±3.3, with a score-reducing rate >50%. Improved N400 indexes were also observed, with shortened N400 latencies and enlarged N400 amplitudes (P<0.05 or P<0.01). Conclusion Cognitive and linguistic disorders can be found in patients with FES, and N400 changes may be a state marker for schizophrenia.

Key words: schizophrenia, N400, evoked potential, risperidone, treatment effect