Rodríguez-Cano Elena, Alonso-Lana Silvia, Sarró Salvador, Fernández-Corcuera Paloma, Goikolea José M, Vieta Eduard, Maristany Teresa, Salvador Raymond, McKenna Peter J, Pomarol-Clotet Edith
FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain.
Benito Menni Complex Assistencial en Salut Mental, Sant Boi, Spain.
Bipolar Disord. 2017 Aug;19(5):386-395. doi: 10.1111/bdi.12517. Epub 2017 Jul 17.
Neuroimaging studies have revealed evidence of brain functional abnormalities in bipolar depressive disorder (BDD) and major depressive disorder (MDD). However, few studies to date have compared these two mood disorders directly.
Matched groups of 26 BDD type I patients, 26 MDD patients and 26 healthy controls underwent functional magnetic resonance imaging (fMRI) while performing the n-back working memory task. A whole-brain ANOVA was used to compare the three groups and clusters of significant difference were examined further using region-of-interest (ROI) analysis.
The whole-brain ANOVA revealed a single cluster of significant difference in the medial frontal cortex. The BDD and MDD patients both showed failure to deactivate in this area compared to the controls. The BDD patients showed significantly greater failure of deactivation than the MDD patients, which was not accounted for by differences in severity or chronicity of illness between them.
Failure of deactivation, considered to reflect default mode network dysfunction, is present to a greater extent in bipolar than unipolar depression. The study of this network may be useful in the search for brain markers that distinguish the two disorders.
神经影像学研究已揭示双相抑郁障碍（BDD）和重度抑郁障碍（MDD）存在脑功能异常的证据。然而，迄今为止很少有研究直接比较这两种心境障碍。
26例I型BDD患者、26例MDD患者和26名健康对照组成匹配组，在执行n-back工作记忆任务时接受功能磁共振成像（fMRI）检查。采用全脑方差分析比较三组，并用感兴趣区（ROI）分析进一步检查显著差异簇。
全脑方差分析显示内侧前额叶皮质有一个显著差异簇。与对照组相比，BDD和MDD患者在该区域均表现出失活失败。BDD患者的失活失败显著大于MDD患者，这并非由他们之间疾病严重程度或慢性病程的差异所导致。
失活失败被认为反映默认模式网络功能障碍，在双相抑郁中比单相抑郁更明显。对该网络的研究可能有助于寻找区分这两种障碍的脑标志物。
