State and trait markers of emotionally charged visual event-related potentials (P300) in drug-naïve schizophrenia

Authors


Kiichiro Morita, MD, PhD, Cognitive and Molecular Research Institute, Kurume University School of Medicine, 67 Asahi-Machi, Kurume 830-0011, Japan. Email: kiichiro@med.kurume-u.ac.jp

Abstract

Aim:  In the present study, we investigated the changes in P3 component in the emotionally charged visual event-related potentials (ERP) in 30 drug-naïve schizophrenic patients for up to 1 year.

Methods:  Visual oddball event-related potential was recorded from six recording sites for crying baby or smiling baby photographs. ERP were recorded before the treatment (session 1 [S1]), after 3 months (session 2 [S2]), and after 12 months (session 3 [S3]), as well as in 30 healthy subjects.

Results:  Before taking medicine, there were no significant differences in the P300 amplitude between viewing photographs of a crying and a smiling baby. The P300 amplitude was significantly larger at S2 and S3 than at S1 for a crying baby, while there was no significant difference among sessions for a smiling baby after medication. A significant difference of the P300 amplitude was only observed between S3 and healthy subjects for a smiling baby. The P300 latency only when viewing a smiling face became significantly longer at S3 than those at S1 and S2. A significant negative correlation was obtained between the P300 amplitude changes upon viewing crying faces and negative syndrome score changes at the Pz site.

Conclusion:  The P300 amplitude induced by crying-face stimuli may be a state marker and the P300 amplitude caused by smiling-face stimuli may be a trait marker during recovery in schizophrenic patients. Atypical antipsychotic medications may be useful and may recover cognitive function reflected by the emotionally charged visual P300 components in schizophrenic patients.

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