RESUMO
Objective To explore the changing indications of visual P300 evoked by facial expression stimulus in social anxiety disorder (SAD). Methods 30 patients with SAD were consecutively recruited, and matched with 30 normal controls (NC). They were evaluated by self-designed demographic questionnaire and Liebowitz Social Anxiety Scale (LSAS), Meanwhile the examination of the visual P300 evoked by five facial expression stimulus included sad, happy, surprise, angry and disgust was administrated to SAD patients and normal controls. Results Compared with NC group, SAD group had higher target P2 amplitudes ( ( 3.73 ± 3.06 ) μV )and higher target P3 amplitudes( ( 9.43 ± 4.01 ) μV ) evoked by angry facial expression (P＜ 0.05 ) and higher target P3 amplitudes( (9.57 ±4.42) μV) evoked by disgust facial expression (P＜0.05). The scores of LSAS in SAD was positively correlated with target P2 amplitudes (P＜0.05). Conclusion SAD group has abnormal changing indications of visual P300 evoked by facial expression stimulus.