Association of Psychological Resilience with Decelerated Brain Aging in Cognitively Healthy World Trade Center Responders

Background. Despite their exposure to potentially traumatic stressors, the majority of World Trade Center (WTC) responders – those who worked on rescue, recovery, and cleanup efforts on or following September 11th, 2001 – have shown psychological resilience, never developing long-term psychopathology. Psychological resilience may be protective against the earlier age-related cognitive changes associated with posttraumatic stress disorder (PTSD) in this cohort. The current study estimated the difference between estimated brain age from structural MRI data and chronological age in WTC responders who participated in a parent fMRI study of resilience (N=97). We hypothesized that highly resilient responders would show the least brain aging, and explored associations between brain aging and psychological and cognitive measures. Method. WTC responders screened for absence of cognitive impairment were classified into three groups: WTC-related PTSD group (n=32), Highly Resilient (n=34) group without lifetime psychopathology despite high WTC-related exposure, and Lower WTC-Exposed (n=31) control group also without lifetime psychopathology. We used BrainStructureAges, a deep learning algorithm that estimates voxelwise age from T1-weighted MRI data, to calculate decelerated (or accelerated) brain aging relative to chronological age (“BSAGE gap”).Results. Globally, brain aging was decelerated in the Highly Resilient group and accelerated in PTSD, with a significant group difference (p=.021, Cohen’s d=0.58); the Lower WTC-Exposed control group exhibited no significant brain age gap or group difference. Lesser brain aging was associated with resilience-linked factors including lower emotional suppression, greater optimism, and better verbal learning. Conclusions. Cognitively healthy WTC responders show differences in brain aging related to resilience and PTSD.