Depressive symptoms following a stressful life event, such as a relationship breakup, are common, and constitute a potent risk factor for the onset of a major depressive episode. Resting-state neuroimaging studies have increasingly identified abnormal whole-brain communication in patients with depression, but it is currently unclear whether depressive symptoms in individuals without a clinical diagnosis have reliable neural underpinnings. We investigated to what extent the severity of depressive symptoms in a non-clinical sample was associated with imbalances in the complex dynamics of the brain during rest. To this end, a novel intrinsic ignition approach was applied to resting-state neuroimaging data from sixty-nine participants with varying degrees of depressive symptoms following a relationship breakup. Ignition-based measures of integration, hierarchy, and metastability were calculated for each participant, revealing a negative correlation between these measures and depressive ratings. We found that the severity of depressive symptoms was associated with deficits in the brain’s capacity to globally integrate and process information over time. Furthermore, we found that increased depressive symptoms were associated with reduced spatial diversity (i.e., hierarchy) and reduced temporal variability (i.e., metastability) in the functional organization of the brain. These findings suggest the merit of investigating constrained dynamical complexity as it is sensitive to the level of depressive symptoms even in a non-clinical sample.

压力性生活事件（例如关系破裂）后出现的抑郁症状很常见，并且构成重度抑郁发作的潜在危险因素。静息态神经影像学研究越来越多地发现抑郁症患者的全脑通讯异常，但目前尚不清楚未经临床诊断的个体的抑郁症状是否具有可靠的神经基础。我们研究了非临床样本中抑郁症状的严重程度与休息期间大脑复杂动态失衡的相关性。为此，我们将一种新颖的内在点火方法应用于 69 名在关系破裂后有不同程度抑郁症状的参与者的静息态神经影像数据。为每个参与者计算了基于点火的整合、层次和亚稳定性测量，揭示了这些测量与抑郁评级之间的负相关。我们发现抑郁症状的严重程度与大脑随着时间的推移整体整合和处理信息的能力的缺陷有关。此外，我们发现抑郁症状的增加与大脑功能组织的空间多样性（即层次结构）减少和时间变异性（即亚稳定性）减少有关。这些发现表明研究受限动态复杂性的优点，因为即使在非临床样本中，它对抑郁症状的水平也很敏感。