Participants
Data for the current analyses were collected as part of the multisite ED AURORA study. Trauma-exposed civilians brought to one of 29 participating EDs across the United States were recruited for this large, longitudinal study (details in24,28). This investigation included n=2,772 AURORA participants with clinical item-level data at 2-weeks or 6-months recruited from 09/2017 to 12/2020 (Final freeze 4 Psychometric release). Missing data values were excluded listwise, resulting in n=1,835 (1,175 women; Table 1) participants with complete 6-month item level clinical data usable for analyses.
Participants recruited for AURORA at one of the 22 ED sites that funneled participants to one of the five “deep phenotyping” sites were invited to undergo an MRI scan. Functional MRI (fMRI) data were collected for n=445; the fMRI scan included a response inhibition paradigm (n=428), a fearful faces “social threat” task (n=431), and a monetary reward processing task (n=427). Functional data were excluded from analyses for anatomical concerns (n=7), lack of expected behavioral responses or available data (inhibition, n=45; threat, n=14; reward, n=26), excessive motion (any run with >15% of volumes exceeding 1mm FD; inhibition, n=33; threat, n=25; reward, n=45), technical issues during the scan (inhibition, n=14; threat, n=15; reward, n=24). Final data were available for n=385 for at least one of the tasks (n=329 for inhibition, n=370 for threat processing, and n=325 for reward processing). Of these, associations with resilience factor scores were investigated for n=260 individuals who had scores available (Table 1; n=215 for inhibition, n=249 for threat processing, and n=214 for reward processing). Dynamic resilience factor scores (both complete 2-week and 6-month clinical data) were investigated for respectively n=189, n=221, and n=189.
Principal component analyses defining resilience factor
Using principal component analyses (PCA) of self-reports from 6-months post-trauma, three factors were extracted based on eigenvalues greater than 2 (Table 2). The main resilience factor for global stress, or r-factor reflected general mental wellbeing following trauma (eigenvalue=23.52). Two additional factors were identified, one labeled as reminder acceptance (eigenvalue=2.39), which represents low levels of re-experiencing and avoidance of reminders of the traumatic event, and a second labeled behavioral control (eigenvalue=2.17), which represents low levels of the impulsivity, risk taking, loss of control and feeling rejected, that often follow a major stressor. Notably, the highest loadings for each of the three factors bridged multiple instruments and domains, suggesting that the data support a transdiagnostic approach.
Evaluating demographic characteristics of the factor scores (Table 3) showed that men had greater mean scores of reminder acceptance, whereas women had greater behavioral control scores. Older age correlated with r-factor scores and behavioral control, but less reminder acceptance. Because age and sex contributed to variance of interest in the factor scores and indeed showed associations with the factor scores, they were not again included as covariates in the neuroimaging analyses. Greater childhood trauma, as measured with an abbreviated version of the Childhood Trauma Questionnaire (CTQ), correlated with lower scores for r, reminder acceptance, and behavioral control (Table 3). Correlation values for reminder acceptance were small, and not statistically significant for childhood neglect. Greater levels of trait resilience assessed by the Connor-Davidson Resilience Scale (CD-RISC) positively correlated with r, and (modestly) with behavioral control, but not with reminder acceptance (Table 3).
Dynamic resilience was calculated by estimating factor scores for the 2-week data based on the 6-month data and computing difference scores. There was a statistically significant increase in the score over time (2-weeks to 6-months) for the r-factor and reminder acceptance, but a decrease for behavioral control (Supplementary Table S1). The static and dynamic resilience scores were all statistically significantly correlated, but shared only 19% to 27% of variance (r-factor, r=0.44; reminder acceptance, r=0.52; behavioral control, r=0.46). Finally, the static and dynamic resilience scores did not significantly differ statistically between participants who were included in the neuroimaging analyses and those not (Supplementary Table S2).
ROI analyses for static and dynamic resilience
r-factor
Greater OFC reactivity to monetary reward 2-weeks post-trauma predicted resilience 6-months post-trauma (static r-factor; r=0.14, p=0.042; Fig. 2) and a greater increase in resilience from 2-weeks to 6-months post-trauma (dynamic r-factor; r=0.27, p<0.001*; Fig. 3). As indicated by the asterisk (*), the dynamic r-factor correlation survives additional correction for multiple comparisons across all nine ROIs and for the two types of resilience (18 tests, p<0.0028). There were no statistically significant associations between the static or dynamic r-factor and ROIs from the threat or inhibition tasks.
Reminder acceptance
Lower 2-week hippocampal reactivity to social threat cues predicted reminder acceptance at 6-months (static reminder acceptance; r=-0.20, p=0.002*; Fig 2) and a greater increase of reminder acceptance from 2-weeks to 6-months post-trauma (dynamic reminder acceptance; r=-0.17, p=0.012; Fig 2). There were not statistically significant predictors of static or dynamic reminder acceptance in the reward or inhibition tasks.
Behavioral control
No statistically significant correlations with static or dynamic behavioral control were observed within the a priori ROIs for any of the three fMRI paradigms.
Whole brain analyses for static and dynamic resilience
r-factor
Figure 3 and Table 4 show statistically significant whole brain correlations with static and dynamic r-factor scores across tasks. The static r-factor scores did not correlate with whole brain activation in the inhibition or threat tasks. During reward processing, the static r-factor positively correlated with activation in the right superior temporal gyrus (STG) and insula, such that greater reward-related activation in these regions 2 weeks post-trauma was related to greater levels of resilience 6-months post-trauma. Additionally, the static r-factor score negatively correlated with activation in the bilateral precuneus* and left inferior parietal lobe (IPL)* reactivity, such that less reward-related activation was related to greater resilience. As indicated by an asterisk (*), the negative correlations were robust to additional study-wide Bonferroni corrections for all whole-brain analyses, across three tasks, three factors, and static and dynamic resilience (18 tests, p<0.0028).
The dynamic r-factor showed associations with the reward and threat tasks, but no associations were observed with the inhibition task. During reward processing, the dynamic r-factor positively correlated with activation in the bilateral superior frontal gyrus (SFG)*, bilateral insula*, left superior medial gyrus (SMG)*, and dACC*, such that greater reward-related activation 2-weeks post-trauma predicted a greater increase in the r-factor between 2-weeks and 6-months post-trauma. During threat processing, the r-factor was negatively correlated with activation in the bilateral IPL* such that lower threat reactivity 2-weeks post-trauma was associated with a greater increase in r.
Reminder acceptance
There were no statistically significant results for the whole brain correlations between static or dynamic reminder acceptance and the inhibition, threat, or reward contrasts (Table 4).
Behavioral control
Figure 4 and Table 4 show statistically significant whole brain correlations with behavioral control across tasks. No correlations were observed between static behavioral control scores and neural responses to threat. During inhibition, the static behavioral control score was positively correlated with activation in the right inferior frontal gyrus (rIFG), such that greater rIFG reactivity 2-weeks post-trauma was related to greater behavioral control 6-months post-trauma. During reward processing, the static behavioral control score was negatively correlated with left pre/postcentral gyrus activation, such that less activation was related to greater behavioral control six months post-trauma.
Dynamic behavioral control analyses showed positive correlations for both reward and threat processing, but no associations with the inhibition task were observed. During reward processing, the dynamic behavioral control score positively correlated with activation in the right IPL* and right insula, such that greater activation in these regions was associated with greater increase in behavioral control from 2-weeks to 6-months post-trauma. Similarly, during threat processing, the dynamic resilience score positively correlated with activation in the bilateral IPL* and bilateral postcentral gyrus* and left precentral gyrus, such that greater threat reactivity in these regions was associated with a greater increase in behavioral control.