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Although acute impact of traumatic experiences on brain function in disaster survivors is similar to that observed in post-traumatic stress disorders (PTSD), little is known about the long-term impact of this experience. We have used structural and functional magnetic resonance imaging to investigate resting-state functional connectivity and gray and white matter (WM) changes occurring in the brains of healthy Wenchuan earthquake survivors both 3 weeks and 2 years after the disaster. Results show that while functional connectivity changes 3 weeks after the disaster involved both frontal-limbic-striatal and default-mode networks (DMN), at the 2-year follow-up only changes in the latter persisted, despite complete recovery from high initial levels of anxiety. No gray or WM volume changes were found at either time point. Taken together, our findings provide important new evidence that while altered functional connectivity in the frontal-limbic-striatal network may underlie the post-trauma anxiety experienced by survivors, parallel changes in the DMN persist despite the apparent absence of anxiety symptoms. This suggests that long-term changes occur in neural networks involved in core aspects of self-processing, cognitive and emotional functioning in disaster survivors which are independent of anxiety symptoms and which may also confer increased risk of subsequent development of PTSD., (© The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.)

A characterization of the impact of natural disasters on the brain of survivors is critical for a better understanding of posttraumatic responses and may inform the development of more effective early interventions. Here we report alterations in white matter microstructure in survivors soon after Wenchuan earthquake in China in 2008. Within 25 days after the Wenchuan earthquake, 44 healthy survivors were recruited and scanned on a 3T MR imaging system. The survivors were divided into two groups according to their self-rating anxiety scale (SAS) score, including the SAS(+) (SAS > 55 after correction) group and "SAS(-)" (SAS < 55 after correction) group. Thrity-two healthy volunteers were also recruited as control group before earthquake. Individual maps of fractional anisotropy (FA) were calculated and voxel-based analysis (VBA) was performed to allow the comparison between survivors and controls using ANCOVAs in SPM2. In addition, a correlation between SAS score and regional FA value was examined using Pearson's correlation analysis in SPSS 11.5. Compared with the healthy cohort, the whole group of 44 survivors showed significantly decreased FA values in the right prefrontal lobe, the parietal lobe, the basal ganglia, and the right parahippocampus. These effects did not appear to depend on self-rating anxiety. For the first time we provide evidence that acute trauma altered cerebral microstructure within the limbic system; furthermore, these alterations are evident shortly after the traumatic event, highlighting the need for early evaluation and intervention for trauma survivors., (Copyright © 2011 Wiley Periodicals, Inc.)