中文摘要：

目的利用静息态功能磁共振成像（resting—state functional magnetic resonance imaging，rfMRI）技术研究首发未用药重性抑郁障碍患者抗抑郁药物治疗前后脑局部一致性（regional homogeneity，ReHo）的变化。方法对25例首发未用药重性抑郁障碍患者分别于治疗前和治疗8周后进行静息态功能磁共振扫描，采用配对t检验分析组间差异。结果与治疗前相比，经8周抗抑郁药物有效治疗后首发未用药重性抑郁障碍患者右侧额内侧回、左侧顶下小叶、左侧颞中回、左侧脑岛、右侧楔前叶、左侧内侧和旁扣带回、双侧小脑后叶ReHo值降低（校正前单个体素P〈0．001，AlphaSim多重比较校正矗≥6）；右侧额中回、左侧额内侧回、右侧顶下小叶、左侧中央后回、右侧颞中回ReHo值增高（校正前单个体素P〈0．001，AlphaSim多重比较校正k≥6）。结论首发未用药重性抑郁障碍患者默认网络存在广泛功能异常，这可能是抑郁障碍发病的神经基础，经8周抗抑郁药物治疗后，功能异常可部分逆转；基于ReHo的静息态fMRI技术可以动态评价抗抑郁药物的疗效。

英文摘要：

Objective To examine the values of Regional Homogeneity （ReHo） in first-episode, treatment-naive patients with major depressive disorder before and after antidepressant treatment in order to explore the neural mechanism of antidepressants. Methods Twenty-five first-episode, treatment-naive patients with major depressive disorder, which met with DSM-IV diagnosis criteria underwent fMRI resting-state scans before and after 8-week antidepressant treatment. Paired Samples T-test was used to analysis the differences between two groups. Results The ReHo in the patient group after treatment were significantly decreased in the right medial frontal gyrus, left inferior parietal lobule, left middle temporal gyrus, left insula, right precuneus, left cingulate gyrus and posterior lobe of the cerebellum, while significantly increased in the right medial frontal gyms, left medial frontal gyrus, right inferior parietal lobule, left postcentral gyrus and fight middle temporal gyrus compared with before treatment. Conclusions Extensive abnormal activity within the default mode network in the resting-state may be involved in the neuropathophylogical substrate of depression and the abnormal activity can be partly reversed by antidepressant treatment, suggesting that regional homogeneity can be used to dynamically evaluate the effect of antidepressant treatment.