Brain Volume in Veterans: Relationship to Posttraumatic Stress Disorder and Mild Traumatic Brain Injury.

OBJECTIVE

Clarify associations between diagnosis of posttraumatic stress disorder (PTSD) and deployment traumatic brain injury (TBI) on salient regional brain volumes in returning combat veterans.

PARTICIPANTS

Iraq and Afghanistan era combat veterans, N = 163, 86.5% male.

MAIN MEASURES: Clinician-administered PTSD Scale (CAPS-5), Mid-Atlantic MIRECC Assessment of TBI (MMA-TBI), magnetic resonance imaging.

METHODS

Hierarchical regression analyses evaluated associations and interactions between current and lifetime PTSD diagnosis, deployment TBI, and bilateral volume of hippocampus, anterior cingulate cortex, amygdala, orbitofrontal cortex, precuneus, and insula.

RESULTS

Deployment TBI was associated with lower bilateral hippocampal volume (P = .007-.032) and right medial orbitofrontal cortex volume (P = .006). Neither current nor lifetime PTSD diagnosis was associated with volumetric outcomes beyond covariates and deployment TBI.

CONCLUSION

History of deployment TBI is independently associated with lower volumes in hippocampus and medial orbitofrontal cortex. These results support TBI as a potential contributing factor to consider in reduced cortical volume in PTSD.