Brain network dynamics following induced acute stress: A neural marker of psychological vulnerability to real-life chronic stress

Background Stress leads to neurobiological changes, and failure to regulate these can contribute to chronic psychiatric issues. Despite considerable research, the relationship between neural alterations in acute stress and coping with chronic stress is unclear. This longitudinal study examined whole-brain network dynamics following induced acute stress and their role in predicting chronic stress vulnerability. Methods Sixty military pre-deployment soldiers underwent a lab-induced stress task where subjective stress and resting-state functional magnetic resonance imaging were acquired repeatedly (before stress, after stress, and at recovery, 90 min later). Baseline depression and post-traumatic stress symptoms were assessed, and again a year later during military deployment. We used the Leading Eigenvector Dynamic Analysis framework to characterize changes in whole-brain dynamics over time. Time spent in each state was compared across acute stress conditions and correlated with psychological outcomes. Results Findings reveal significant changes at the network level from acute stress to recovery, where the frontoparietal and subcortical states decreased in dominance in favor of the default mode network, sensorimotor, and visual states. A significant normalization of the frontoparietal state activity was related to successful psychological recovery. Immediately after induced stress, a significant increase in the lifetimes of the frontoparietal state was associated with higher depression symptoms (r = 0.49, p <.02) and this association was also observed a year later following combat exposure (r = 0.49, p <.009). Conclusions This study revealed how acute stress-related neural alterations predict chronic stress vulnerability. Successful recovery from acute stress involves reducing cognitive-emotional states and enhancing self-awareness and sensory-perceptual states. Elevated frontoparietal activity is suggested as a neural marker of vulnerability to chronic stress.