Eyre Harris A, Yang Hongyu, Leaver Amber M, Van Dyk Kathleen, Siddarth Prabha, Cyr Natalie St, Narr Katherine, Ercoli Linda, Baune Bernhard T, Lavretsky Helen
Discipline of Psychiatry, University of Adelaide, Adelaide, South Australia, Australia; Semel Institute for Neuroscience and Human Behavior, UCLA, USA.
Semel Institute for Neuroscience and Human Behavior, UCLA, USA.
J Affect Disord. 2016 Jan 1;189:126-33. doi: 10.1016/j.jad.2015.09.011. Epub 2015 Sep 28.
Disrupted brain connectivity is implicated in the pathophysiology of late-life depression (LLD). There are few studies in this area using resting-state functional magnetic resonance imaging (rs-fMRI). In this pilot case-control study, we compare rs-fMRI data between age-matched depressed and non-depressed older adults.
Older participants (≥55 years) with current major depressive disorder (MDD) were recruited to participate in an ongoing study of LLD, and were compared to the age-matched, non-depressed controls. Rs-fMRI data were collected using a 3-Tesla MRI system. In this study, a data-driven approach was chosen and an independent component analysis (ICA) was performed.
Seventeen subjects with MDD were compared to 31 controls. The depressed group showed increased connectivity in three main networks compared to the controls (p(corr)<0.05), including connectivity between the default mode network (DMN) and the posterior superior temporal sulcus (pSTS). Increased connectivity was also observed within the visual network in the medial, lateral and ventral regions of the occipital lobes, and within the auditory network throughout the right superior temporal cortex.
This data-driven, pilot study finds patterns of increased connectivity that may be unique to LLD in the DMN, as well as visual and auditory networks. The functional implications of this aberrant connectivity remains to be determined. These findings should be further explored in larger samples.
大脑连接中断与老年期抑郁症（LLD）的病理生理学有关。在这一领域，使用静息态功能磁共振成像（rs-fMRI）的研究较少。在这项探索性病例对照研究中，我们比较了年龄匹配的抑郁和非抑郁老年人的rs-fMRI数据。
招募患有当前重度抑郁症（MDD）的老年参与者（≥55岁）参与一项正在进行的LLD研究，并将其与年龄匹配的非抑郁对照组进行比较。使用3特斯拉磁共振成像系统收集rs-fMRI数据。在本研究中，选择了一种数据驱动的方法并进行了独立成分分析（ICA）。
将17名患有MDD的受试者与31名对照组进行比较。与对照组相比，抑郁组在三个主要网络中的连接性增加（p（校正）<0.05），包括默认模式网络（DMN）与后颞上沟（pSTS）之间的连接。在枕叶内侧、外侧和腹侧区域的视觉网络内以及整个右侧颞上皮质的听觉网络内也观察到连接性增加。
这项数据驱动的探索性研究发现了连接性增加的模式，这些模式可能是LLD在DMN以及视觉和听觉网络中所特有的。这种异常连接的功能意义仍有待确定。这些发现应在更大的样本中进一步探索。
