抑郁症患者处理喜悦面孔时边缘环路异常具有状态性

State or trait？ The aberrant effective connections of limbic circuits in recognition to happy face among depressed patients before and after antidepressant treatment

目的探讨抑郁症患者识别正性情绪时边缘环路异常的效能连接和抗抑郁治疗对边缘环路的影响，以及异常的效能连接是否具有状态性。方法对12例抑郁症患者（抑郁症组）、12名相匹配的健康对照者（对照组）进行脑磁图扫描，经过8~10周规范化抗抑郁药治疗后再次对抑郁症患者进行脑磁图扫描，选取喜悦表情刺激下的脑磁信号，眶额回、前扣带回、杏仁核、海马、脑岛5个脑区作为感兴趣区，应用SPM8软件进行数据预处理及源重建，提取感兴趣时间窗0~600 ms时间序列，进行主成分方法降维，利用格兰杰因果模型进一步计算出各感兴趣脑区之间的效能连接值，采用单因素方差分析方法比较抑郁症组治疗前后与对照组效能连接的差异。结果（1）单因素方差分析显示，抑郁症治疗前、后与对照组3组效能连接值比较差异有统计学意义的是：眶额回到杏仁核的效能连接（F=3.927，P=0.030），杏仁核到海马的效能连接（F=7.470，P=0.002，FDR校正），脑岛到杏仁核的效能连接（F=3.361，P=0.047），海马到杏仁核的效能连接（F=4.132，P=0.025）。（2）抑郁症组治疗前与对照组比较：眶额回到杏仁核效能连接增强（P=0.040），前扣带回到海马效能连接减弱（P=0.042），杏仁核到海马效能连接减弱（P=0.001），海马到杏仁核效能连接减弱（P=0.026）。（3）抑郁症组治疗后与治疗前比较：眶额回到杏仁核效能连接减弱（P=0.013），杏仁核到海马效能连接增强（P=0.006），海马到杏仁核效能连接增强（P=0.026），杏仁核到脑岛效能连接减弱（P=0.036），脑岛到杏仁核效能连接减弱（P=0.015）。（4）抑郁症组治疗后与对照组差异无统计学意义。结论抑郁症患者识别正性情绪时边缘环路交互异常可能是抑郁症患者正性情绪处理异常的重要机制之一，抗抑郁治疗后随着症状缓解而改善，提示正性情绪处理异常具有状态性，可能在抑郁症的发病机制中发挥重要作用。

Objective To investigate the aberrant effective connections of limbic circuits in patients with major depressive disorder when they recognized dynamic positive face expressions before and after antidepressant treatment, and to further explore whether the abnormal happy facial emotion processing was a state abnormality or a trait defect？ Methods Twelve depressed patients and 12 well-matched healthy control volunteers participated in the study. All the subjects were scanned by magnetoencephalograph （MEG） when recognizing the emotion face images. Subjects in depression group were again performed the face recognition and MEG scanning after 8-10 weeks of standard antidepressant treatment. The MEG signals in response to happy face among orbitalfrontal cortex （OFC）, the anterior cingulated cortex （ACC）, the amygdala （AMYG）, the hippocampus （Hipp）, and the insula （Insu） were recorded at 0-600 ms. Principal component analysis （PCA） was used to reduce the dimensions, and the effective connectivity of the above interested brain areas was computed and tested by Granger causality model （GCM）. The differences of effective connectivity in the interested brain areas between depressed patients and healthy control were analyzed by one-way ANOVA.Results （1）Among the above three groups, significant differences of effective connections were found in the connections of OFC to AMYG （F=3.927, P=0.030）, Hipp to AMYG （F=4.132, P=0.025）, Insu to AMYG （F=3.361, P=0.047）, and AMYG to Hipp （F=7.470, P=0.002, FDR correction）. （2） Compared with the healthy control group, the depressed patients before antidepressants treatment displayed higher activity in effective connections from OFC to AMYG （P=0.040）, lower activity in effective connections from the ACC to the Hipp （P=0.042）, and lower activity in effective connections both from AMYG to Hipp （P=0.001） and hipp to AMYG （P=0.026）. （3） After antidepressants treatment, the activity of effective connections from the OFC to the AMYG significantly reduced （P=0.013）, and the activity of connections both from AMYG to Hipp and from Hipp to AMYG significantly increased （P=0.006, 0.026）, while the activity of effective connections both from AMYG to Insu and from Insu to AMYG significantly reduced （P=0.036, P=0.015）. （4） Depressed patients after treatment showed no significant difference compared with the healthy control group.Conclusions The aberrant effective connection of the limbic system during positive emotion processing tasks may play an important role in explaining the abnormal positive emotion processing in depressed patients, which is a state abnormality instead of a trait defect, supported by the full recovery after antidepressant treatment.