抑郁症首次发作患者情绪偏向任务的脑功能磁共振成像研究

目的 研究抑郁症首次发作(以下简称首发)患者对不同性质情绪线索的差异脑激活反应,以探讨抑郁症患者"负性情绪偏向性"的脑活动特征.方法 14例抑郁症首发患者与14名配对健康对照者,接受国际情绪图片系统中正性-中性-负性三组图片刺激的脑功能磁共振成像(fMRI)扫描,任务为组块设计;以文拉法辛(75～150 mg/d,口服)治疗患者,随访12周;以汉密尔顿抑郁量表(HAMD17)减分率评估疗效;用神经功能影像分析(AFNI)软件处理影像数据.结果 (1)文拉法辛治疗8周时有效率为58%;12周时有效率为92%,HAMD17总分减分率为60%.(2)两组均激活的脑区包括双侧额中回、双侧背外侧前额叶皮质、左侧丘脑、双侧岛叶、双侧颞叶、双侧杏仁核和海马.(3)在正性/中性图片激活的脑区中,患者组双侧额中回(右侧0.11%,左侧0.09%)及左侧丘脑(0.31%)激活强度均低于对照组(分别为0.98%,1.17%和1.32%;P＜0.05);左侧岛叶(1.03%)及双侧杏仁核(右侧0.47%,左侧0.11%)的激活强度高于对照组(分别为0.45%,-0.34%和-0.49%;P＜0.05).对于负性图片,患者组左侧额中回(2.77%)、左背外侧前额叶皮质(0.18%)、左侧岛叶(1.36%)、左侧颞叶(0.33%)和右侧杏仁核(0.44%)的激活强度高于对照组(分别为1.91%.-0.32%.0.91%,-0.31%,-0.29%;P＜0.05);患者组左侧丘脑激活强度(-0.79%)低于对照组(1.15%;P＜0.05).(4)治疗后,对于正性图片,患者组左侧、右侧额中回及左侧丘脑激活增加为1.21%,1.14%及1.23%(P＜0.05).对于负性图片,左侧额中回(2.05%)、左外侧前额叶皮质(-0.42%)及左侧岛叶(0.73%)的激活降低(P＜0.05);左侧丘脑(1.53%)激活增加(P＜0.05).结论 前额叶、左侧岛叶、左侧颞叶、杏仁核和左侧丘脑对不同性质情绪诱导线索的异常激活,与抑郁症首发患者偏向性情绪障碍相关;文拉法辛对前额叶、左侧岛叶和丘脑的异常激活有调节作用.

The neural substrate of bias mood-processing in patients with first-episode depression: a functional magnetic resonance imaging study with emotional picture stimuli

Objeefive To explore the neural substrate of bias mood-processing in depression by probing the differences of neural activation associated with reactivity to different affective stimuli clues.Methods Forteen patients with depressive disorder and 14 healthy subjects were scanned with functional magnetic resonance imaging(fMRI)on three occasions based on block-design,during whicn positive,neutral and negative affective visual stimuli from International Affective Pictures System(IAPS)were presented Patients were then treated with venlafaxine(75-150 mg/d)for 12 weeks,and the symptoms were evaluated with the Hamilton Depression Scale(HAMD17).The Analyze of functional neural xmage (AFNI)was used to examine the fMRI data.Results The respective response rates were 58%and 92%after 8-and 12-week venlafaxine treatment,with the total reduction rate of HAMD17 score of 60%. The activated cerebral regions in both patients and controls included bilateral middle frontal gyrus,bilateral dorsolateral prefrontal cortex,lefl thalamus,bilateral insular,bilateral temporal,bilateral amygdale and hippocampus.For positive pictures,the activation intensity levels in right middle frontal gynm,left middle frontal gyrus and left thalamus in patients were 0.11%.0.09%and 0.31%respectively.which were significantly lower than that in controls(0.98%,1.17%and 1.32%respectively;P＜0.05).and the activation intensity levels in left insular,risht amygdale and left amygdale were 1.03%,0.47%and 0.11%in patients,which were significantly hisher than that in controls(0.45%. -0.34%and-0.49%respectively;P＜0.05).For negative pictures,the activation intensity levels in left middle frontal gyrus,left dorsolateral prefrontal cortex,left insular,left temporal and risht amygdale were 2.77%,0.18%,1.36%,0.33%and 0.44%,which were hisher than that in controls(1.91%,-0.32%,0.91%,-0.31%,-0.29%respectively;P＜0.05);the activation intensity level in left thalamus was lower than that of the control(-0.79%vs.1.15%;P＜0.05).After venlafaxine treatment,for positive pictures.the increases of the activation intensity levels in bilateral middle frontal gyrus and left thaiamus were 1.21%,1.14%and 1.23%respectively(P＜0.05),and for negative pictures.the decreases of the activation intensity levels in left middle frontal gyrus.left dorsolateral prefrontal cortex and left insular were 2.05%,-0.42%and 0.73%respectively(P＜0.05).Conclusions The abnormal activation in prefrontal lobe,left insular,left temporal,amygdale and left thalamus stimulated by different kinds of mood inducing clues may be associated with bias mood processing in the patients with depression.And the abnormal activation of prefrontal lobe.left insular and thalamus can be regulated after venlafaxine treatment.