title: Military deployment correlates with smaller prefrontal gray matter volume and psychological symptoms in a subclinical population.
abstract: Research investigating the effects of trauma exposure on brain structure and function in adults has mainly focused on post-traumatic stress disorder (PTSD), whereas trauma-exposed individuals without a clinical diagnoses often serve as controls. However, this assumes a dichotomy between clinical and subclinical populations that may not be supported at the neural level. In the current study we investigate whether the effects of repeated or long-term stress exposure on brain structure in a subclinical sample are similar to previous PTSD neuroimaging findings. We assessed 27 combat trauma-exposed individuals by means of whole-brain voxel-based morphometry on 3 T magnetic resonance imaging scans and identified a negative association between duration of military deployment and gray matter volumes in ventromedial prefrontal cortex (vmPFC) and dorsal anterior cingulate cortex (ACC). We also found a negative relationship between deployment-related gray matter volumes and psychological symptoms, but not between military deployment and psychological symptoms. To our knowledge, this is the first whole-brain analysis showing that longer military deployment is associated with smaller regional brain volumes in combat-exposed individuals without PTSD. Notably, the observed gray matter associations resemble those previously identified in PTSD populations, and concern regions involved in emotional regulation and fear extinction. These findings question the current dichotomy between clinical and subclinical populations in PTSD neuroimaging research. Instead, neural correlates of both stress exposure and PTSD symptomatology may be more meaningfully investigated at a continuous level.
authors.affiliation: Max Planck Institute for Human Development, Center for Lifespan Psychology, Berlin, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Butler
authors.affiliation: Max Planck Institute for Human Development, Center for Lifespan Psychology, Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Adolf
authors.affiliation: Charité University Medicine, Campus Charité Mitte, Clinic for Psychiatry and Psychotherapy, Berlin, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Gleich
authors.affiliation: Psychotrauma Center of the German Military, Military Hospital Berlin, Berlin, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Willmund
authors.affiliation: Psychotrauma Center of the German Military, Military Hospital Berlin, Berlin, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Zimmermann
authors.affiliation: Max Planck Institute for Human Development, Center for Lifespan Psychology, Berlin, Germany.|European University Institute, Department of Political and Social Sciences, Badia Fiesolana, San Domenico di Fiesole, Italy.|Max Planck UCL Centre for Computational Psychiatry and Ageing Research, Berlin, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Lindenberger
authors.affiliation: University Clinic Hamburg-Eppendorf, Clinic and Policlinic for Psychiatry and Psychotherapy, Hamburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Gallinat
authors.affiliation: Max Planck Institute for Human Development, Center for Lifespan Psychology, Berlin, Germany.|University Clinic Hamburg-Eppendorf, Clinic and Policlinic for Psychiatry and Psychotherapy, Hamburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Kühn
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D066128:Gray Matter / Q000000981:diagnostic imaging* / Q000473:pathology; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008889:Military Personnel; D009929:Organ Size; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging* / Q000473:pathology; D000067073:Psychological Trauma / Q000000981:diagnostic imaging*; D013313:Stress Disorders, Post-Traumatic / Q000000981:diagnostic imaging*; D013997:Time Factors; D000067453:War Exposure; D055815:Young Adult