title: A neurobehavioral account for individual differences in resilience to chronic military stress.
abstract: BACKGROUND
  Military training is a chronic stressful period that often induces stress-related psychopathology. Stress vulnerability and resilience depend on personality trait anxiety, attentional threat bias and prefrontal-limbic dysfunction. However, how these neurobehavioral elements interact with regard to the development of symptoms following stress remains unclear.
  
  
  METHODS
  Fifty-five healthy combat soldiers undergoing intensive military training completed functional magnetic resonance imaging (fMRI) testing while performing the dot-probe task (DPT) composed of angry (threat) and neutral faces. Participants were then stratified according to their bias tendency to avoidance (n = 25) or vigilance (n = 30) groups, categorized as high or low trait anxiety and assessed for post-stress symptom severity.
  
  
  RESULTS
  Avoidance compared to vigilance tendency was associated with fewer post-trauma symptoms and increased hippocampal response to threat among high anxious but not low anxious individuals. Importantly, mediation analysis revealed that only among high anxious individuals did hippocampal activity lead to lower levels of symptoms through avoidance bias tendency. However, in the whole group, avoidance bias was modulated by the interplay between the hippocampus and the dorsal anterior cingulate cortex (dACC).
  
  
  CONCLUSIONS
  Our results provide a neurobehavioral model to explain the resilience to post-trauma symptoms following chronic exposure. The model points to the importance of considering threat bias tendency in addition to personality traits when investigating the brain response and symptoms of trauma. Such a multi-parametric approach that accounts for individual behavioral sensitivities may also improve brain-driven treatments of anxiety, possibly by targeting the interplay between the hippocampus and the dACC.
authors.affiliation: Functional Brain Center,Wohl Institute for Advanced Imaging,Tel Aviv Sourasky Medical Center,Israel.
authors.forename: T
authors.initials: T
authors.lastname: Lin
authors.affiliation: Functional Brain Center,Wohl Institute for Advanced Imaging,Tel Aviv Sourasky Medical Center,Israel.
authors.forename: S
authors.initials: S
authors.lastname: Vaisvaser
authors.affiliation: Division of Mental Health,Medical Corps, IDF,Tel Hashomer,Military Mail,Israel.
authors.forename: E
authors.initials: E
authors.lastname: Fruchter
authors.affiliation: Functional Brain Center,Wohl Institute for Advanced Imaging,Tel Aviv Sourasky Medical Center,Israel.
authors.forename: R
authors.initials: R
authors.lastname: Admon
authors.affiliation: School of Psychological Sciences,Tel-Aviv University,Israel.
authors.forename: I
authors.initials: I
authors.lastname: Wald
authors.affiliation: Mood and Anxiety Disorders Program,Intramural Research Program,The Institute of Mental Health,Bethesda,MD,USA.
authors.forename: D S
authors.initials: DS
authors.lastname: Pine
authors.affiliation: School of Psychological Sciences,Tel-Aviv University,Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Bar-Haim
authors.affiliation: Functional Brain Center,Wohl Institute for Advanced Imaging,Tel Aviv Sourasky Medical Center,Israel.
authors.forename: T
authors.initials: T
authors.lastname: Hendler
mesh_terms: D000293:Adolescent; D001007:Anxiety / Q000503:physiopathology; D001143:Arousal; D001921:Brain / Q000503:physiopathology; D005239:Fear; D059907:Functional Neuroimaging; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D007206:Individuality; D008279:Magnetic Resonance Imaging; D008297:Male; D008889:Military Personnel / Q000523:psychology*; D010551:Personality; D055500:Resilience, Psychological; D040921:Stress Disorders, Traumatic / Q000503:physiopathology* / Q000523:psychology; D013315:Stress, Psychological / Q000503:physiopathology* / Q000523:psychology; D055815:Young Adult
keywords: trait anxiety