Department of Radiology, Beijing Anding Hospital, Capital Medical University, Beijing 100088, China.
Prog Neuropsychopharmacol Biol Psychiatry. 2013 Mar 5;41:52-9. doi: 10.1016/j.pnpbp.2012.11.010. Epub 2012 Nov 28.
Bipolar disorder patients experiencing a depressive episode (BD-dep) without an observed history of mania are often misdiagnosed and are consequently treated as having unipolar depression (UD), leading to inadequate treatment and poor outcomes. An essential solution to this problem is to identify objective biological markers that distinguish BD-dep and UD patients at an early stage. However, studies directly comparing the brain dysfunctions associated with BD-dep and UD are rare. More importantly, the specificity of the differences in brain activity between these mental disorders has not been examined. With whole-brain regional homogeneity analysis and region-of-interest (ROI) based receiver operating characteristic (ROC) analysis, we aimed to compare the resting-state brain activity of BD-dep and UD patients. Furthermore, we examined the specific differences and whether these differences were attributed to the brain abnormality caused by BD-dep, UD, or both.
Twenty-one bipolar and 21 unipolar depressed patients, as well as 26 healthy subjects matched for gender, age, and educational levels, participated in the study. We compared the differences in the regional homogeneity (ReHo) of the BD-dep and UD groups and further identified their pathophysiological abnormality. In the brain regions showing a difference between the BD-dep and UD groups, we further conducted receptive operation characteristic (ROC) analyses to confirm the effectiveness of the identified difference in classifying the patients.
We observed ReHo differences between the BD-dep and UD groups in the right ventrolateral middle frontal gyrus, right dorsal anterior insular, right ventral anterior insular, right cerebellum posterior gyrus, right posterior cingulate cortex, right parahippocampal gyrus, and left cerebellum anterior gyrus. Further ROI comparisons and ROC analysis on these ROIs showed that the right parahippocampal gyrus reflected abnormality specific to the BD-dep group, while the right middle frontal gyrus, the right dorsal anterior insular, the right cerebellum posterior gyrus, and the right posterior cingulate cortex showed abnormality specific to the UD group.
We found brain regions showing resting state ReHo differences and examined their sensitivity and specificity, suggesting a potential neuroimaging biomarker to distinguish between BD-dep and UD patients. We further clarified the pathophysiological abnormality of these regions for each of the two patient populations.
伴有抑郁发作（BD-dep）但无躁狂发作史的双相情感障碍（BD）患者常被误诊为单相抑郁（UD），导致治疗不当和预后不良。解决这个问题的一个重要方法是确定区分 BD-dep 和 UD 患者的客观生物学标志物。然而，直接比较 BD-dep 和 UD 相关脑功能障碍的研究很少。更重要的是，尚未检查这些精神障碍之间脑活动差异的特异性。我们使用全脑区域同质性分析和基于感兴趣区（ROI）的接收者操作特征（ROC）分析来比较 BD-dep 和 UD 患者的静息态脑活动。此外，我们检查了这些差异的特异性，以及这些差异是否归因于 BD-dep、UD 或两者共同导致的脑异常。
21 名双相和 21 名单相抑郁患者以及 26 名性别、年龄和教育程度匹配的健康对照者参加了研究。我们比较了 BD-dep 和 UD 组的局部一致性（ReHo）差异，并进一步确定了它们的病理生理学异常。在显示 BD-dep 和 UD 组之间差异的脑区，我们进一步进行了接收操作特征（ROC）分析，以确认识别的差异在分类患者中的有效性。
我们观察到 BD-dep 和 UD 组之间的右侧腹外侧额中回、右侧背侧前岛叶、右侧腹侧前岛叶、右侧小脑后叶、右侧后扣带回、右侧海马旁回和左侧小脑前叶之间的 ReHo 差异。对这些 ROI 进行进一步的 ROI 比较和 ROC 分析表明，右侧海马旁回反映了 BD-dep 组的特异性异常，而右侧额中回、右侧背侧前岛叶、右侧小脑后叶和右侧后扣带回则反映了 UD 组的特异性异常。
我们发现了显示静息状态 ReHo 差异的脑区，并检查了它们的敏感性和特异性，这表明一种潜在的神经影像学生物标志物可以区分 BD-dep 和 UD 患者。我们进一步阐明了这两个患者群体中这些区域的病理生理学异常。
