Psychological Resilience in World Trade Center Responders is Associated with Effective Brain Network Connectivity

The majority of individuals experience potentially traumatic events in their lifetimes, yet most do not develop severe outcomes such as post-traumatic stress disorder (PTSD). To understand this discrepancy, a growing area of study is psychological resilience, defined as the ability to adapt in response to adversity. Altered connectivity among large-scale brain networks—default mode (DMN), central executive (CEN), and salience (SN)—is well-documented in PTSD. However, less established is these networks’ functioning in highly resilient, such as World Trade Center (WTC) responders who have never developed WTC-related psychopathology despite substantial trauma exposure. We used resting-state fMRI data from a parent study of WTC responders (N=89) to investigate effective network connectivity (i.e., influence of network X on network Y) via Granger causality analysis. Planned contrasts compared three groups: WTC-related PTSD (n=29), high WTC-exposed responders with no psychopathology (“Highly Resilient”, n=32), and lower WTC-exposed controls (n=28). We also examined whether self-report and cognitive measures were correlates of effective network connectivity. We identified a group difference in effective connectivity, with greater influence of CEN on SN in Highly Resilient responders versus Lower WTC-exposed responders. Higher CEN-to-SN connectivity was also associated with better cognitive function in the full sample and with higher estimated IQ in the Highly Resilient group. In conclusion, greater top-down control of SN by CEN may represent a compensatory adaptation after substantial trauma exposure in highly resilient individuals, associated with better cognitive function.