首次发作抑郁症患者认知功能的fMRI研究

The fMRI Study of Cognitive Function in Patients with First Attack Depression

目的利用功能磁共振成像(fMRI)和汉字Stroop任务,探讨抑郁症患者认知功能障碍的神经机制。资料与方法 12例抑郁症患者及12名正常自愿者,采用组块设计的汉字Stroop任务(包括字色一致和字色不一致的颜色命名任务)行fMRI。检查完毕后,行行为学测试,记录总反应时间及错误数。结果字色不一致的颜色命名任务中,与正常对照组相比,抑郁组的反应时间延长(P<0.01),错误数增多(P<0.01)。字色一致的颜色命名任务时,抑郁组出现扣带回的激活。字色不一致的颜色命名任务时,抑郁组左侧前额叶功能脑区激活增加(P<0.05),顶叶多个功能脑区激活减低(P<0.05)。两种任务中,抑郁组左侧前额叶功能脑区激活大于右侧(P<0.05)。结论扣带回-前额叶皮层-顶叶网络异常以及双侧前额叶功能失衡共同构成了抑郁症患者认知障碍的神经基础。

Objective To explore the neural mechanism of cognitive function impairment in patients with depression using fMRI and Stroop task.Materials and Methods Twelve depressive patients and 12 healthy volunteers performed Block-design fMRI with Chinese character Stroop task,which were included two kinds of task：congruous color-naming（CCN） task and incongruous color-naming（ICN）task.Images were analysed using AFNI and all the activating voxels in each task were recorded respectively.After fMRI examinations,behavior tests of Stroop interference were performed for all subjects.Overall reaction time and error numbers were recorded respectively.Results In the ICN task,depressive patients need more reaction time（P0.01）,and made more errors than health controls（P0.01）.In CCN task,depressive patients showed activation in cingulated gyrus.In ICN task,depressive patients showed activation increase in left frontal lobe（P0.05）,while activation decrease in some parietal lobe（P0.05）.Depressive patients showed larger activated voxels in left prefrontal lobe than those in right side in both tasks（P0.05）.Conclusion The abnormal brain network of cingulate gyrus-prefrontal cortex-parietal lobe and the functional imbalance of bilateral prefrontal lobe are the neural mechanism of cognitive impairment in patients with depression.