Kilic B Ülgen, Jubeir Jenna, Balchandani Priti, Murrough James W, Morris Laurel S, Jacob Yael
Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Center for Computational Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Res Sq. 2025 Aug 19:rs.3.rs-7312306. doi: 10.21203/rs.3.rs-7312306/v1.
We investigate the spatiotemporal organization of resting-state brain activity in individuals with and without major depressive disorder (MDD), identifying stable and recurring whole-brain functional co-activation patterns that serve as attractor-like configurations. A particularly prominent brain state, marked by suppressed default mode and frontoparietal networks and heightened salience system engagement, occurring more frequently and with shorter dwell times in MDD and correlating with greater anhedonia severity. Transition dynamics further reveal that MDD participants exhibit reduced transitions between visual-attentional and limbic-default mode systems, which is associated with higher overall depression symptoms, suggestive of affective and cognitive rigidity. By evaluating the dynamic properties in relation to white matter architecture, we find that MDD individuals preferentially transition along energetically costly trajectories, particularly from salience-reactive to introspective states, despite the presence of structurally facilitated alternatives, implicating inefficient structure-function coupling. Finally, characterizing the energetic asymmetries of entry and exit transitions uncovers the landscape on which the brain travels between source- and sink-like attractors, with MDD dynamics disproportionately becoming trapped between a local maximum and a deep basin. These results offer a mechanistic account of how depression may emerge from maladaptive state trajectories within an energetically imbalanced neural landscape.
我们研究了患有和未患有重度抑郁症(MDD)的个体静息态脑活动的时空组织,识别出稳定且反复出现的全脑功能共激活模式,这些模式类似于吸引子构型。一种特别显著的脑状态,其特征为默认模式和额顶叶网络受到抑制,突显系统参与度增加,在MDD中出现得更频繁且停留时间更短,并且与更高的快感缺失严重程度相关。转换动力学进一步揭示,MDD参与者在视觉注意力和边缘 - 默认模式系统之间的转换减少,这与更高的总体抑郁症状相关,提示情感和认知僵化。通过评估与白质结构相关的动态特性,我们发现MDD个体优先沿着能量消耗大的轨迹转换,特别是从突显反应状态转换到内省状态,尽管存在结构上更便利的替代路径,这意味着结构 - 功能耦合效率低下。最后,对进入和退出转换的能量不对称性进行表征,揭示了大脑在类似源和汇的吸引子之间移动的图景,MDD的动力学异常地被困在局部最大值和深谷之间。这些结果为抑郁症如何从能量失衡的神经图景中适应不良的状态轨迹中产生提供了一个机制解释。