Fig. 1.: Flow Chart of Study Participants.

A total number of 321 police recruits participated in the current study. Data from a subsample were acquired for resting-state functional MRI (rs-fMRI) and stress-level-related questionnaires (i.e., PTSD Checklist, PCL; Perceived Stress Scale, PSS) or interviews (i.e., Clinician-Administered PTSD Scale, CAPS), at both Wave-1 and Wave-2 assessments. Following data quality check and the screening of core trauma experiences (i.e., occurrence in-between two assessments), data from a final sample of 190 participants were used for further analyses.