Vanderbilt University School of Medicine, Nashville, Tennessee.
Center for Cognitive Medicine, Department of Psychiatry, Vanderbilt University Medical Center, Nashville, Tennessee.
Biol Psychiatry Cogn Neurosci Neuroimaging. 2019 Feb;4(2):160-170. doi: 10.1016/j.bpsc.2018.09.003. Epub 2018 Sep 21.
Late-life depression (LLD) has been associated with alterations in intrinsic functional networks, best characterized in the default mode network (DMN), cognitive control network (CCN), and salience network. However, these findings often derive from small samples, and it is not well understood how network findings relate to clinical and cognitive symptomatology.
We studied 100 older adults (n = 79 with LLD, n = 21 nondepressed) and collected resting-state functional magnetic resonance imaging, clinical measures of depression, and performance on cognitive tests. We selected canonical network regions for each intrinsic functional network (DMN, CCN, and salience network) as seeds in seed-to-voxel analysis. We compared connectivity between the depressed and nondepressed groups and correlated connectivity with depression severity among depressed subjects. We then investigated whether the observed connectivity findings were associated with greater severity of common neuropsychiatric symptoms or poorer cognitive performance.
LLD was characterized by decreased DMN connectivity to the frontal pole, a CCN region (Wald χ = 22.33, p < .001). No significant group differences in connectivity were found for the CCN or salience network. However, in the LLD group, increased CCN connectivity was associated with increased depression severity (Wald χ > 20.14, p < .001), greater anhedonia (Wald χ = 7.02, p = .008) and fatigue (Wald χ = 6.31, p = .012), and poorer performance on tests of episodic memory (Wald χ > 4.65, p < .031), executive function (Wald χ = 7.18, p = .007), and working memory (Wald χ > 4.29, p < .038).
LLD is characterized by differences in DMN connectivity, while CCN connectivity is associated with LLD symptomology, including poorer performance in several cognitive domains.
老年期抑郁症（LLD）与固有功能网络的改变有关，其中以默认模式网络（DMN）、认知控制网络（CCN）和突显网络的改变最为显著。然而，这些发现往往来自于小样本，并且人们并不清楚网络发现与临床和认知症状有何关系。
我们研究了 100 名老年人（n=79 名患有 LLD，n=21 名无抑郁），并采集了静息态功能磁共振成像、抑郁的临床评估以及认知测试的表现。我们选择了每个固有功能网络（DMN、CCN 和突显网络）的典型网络区域作为种子，进行种子到体素分析。我们比较了抑郁组和非抑郁组之间的连接，并在抑郁组中，将连接与抑郁严重程度相关联。然后，我们研究了观察到的连接发现是否与更严重的常见神经精神症状或较差的认知表现有关。
LLD 的特征是 DMN 与额极的连接减少，CCN 区域（Wald χ=22.33，p<.001）。CCN 或突显网络在抑郁组和非抑郁组之间没有显著的连接差异。然而，在 LLD 组中，CCN 连接的增加与抑郁严重程度的增加（Wald χ>20.14，p<.001）、快感缺失（Wald χ=7.02，p=.008）和疲劳（Wald χ=6.31，p=.012）的增加以及几项认知测试（Wald χ>4.65，p<.031）的表现更差有关，包括情节记忆、执行功能和工作记忆。
LLD 的特征是 DMN 连接的差异，而 CCN 连接与 LLD 症状有关，包括几个认知领域的表现更差。
