Citation

Isaac L, Main KL, Soman S, Gotlib IH, Furst AJ, Kinoshita LM, Fairchild JK, Yesavage JA, Ashford JW, Bayley PJ, Adamson MM. Biol. Psychol. 2015; 105: 20-28.

Affiliation

War Related Illness and Injury Study Center, the Veterans Affairs Palo Alto HealthCare System, Palo Alto, USA; Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA.

Copyright

(Copyright © 2015, Elsevier Publishing)

DOI

10.1016/j.biopsycho.2014.12.011

PMID

25559772

Abstract

A significant proportion of military personnel deployed in support of Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) were exposed to war-zone events potentially associated with traumatic brain injury (TBI), depression (DEP) and posttraumatic stress disorder (PTSD). The co-occurrence of TBI, PTSD and DEP in returning Veterans and the symptom overlap between the three disorders has recently increased both research and clinical interest. The purpose of this study was to test the hypothesis that white matter abnormalities are present and are further impacted by depression. We studied ten prominent white matter tracts. Specifically, the uncinate fasciculus (UF), which is a key fronto-temporal tract involved in mood regulation, and the cingulum a tract that connects to the hippocampus and is involved in memory integration. Both the UF and Cingulum tracts are part of the limbic system, involved in emotion processing, attention and memory, and have been previously implicated in clinical depression. We performed diffusion tensor imaging (DTI) on 25 patients with a combination of PTSD, TBI and DEP and 20 patients with PTSD and TBI but without DEP. Participants were matched on key variables including age, gender distribution and education. Our results provide evidence of microstructural changes of white matter in the Cingulum and UF. Fractional anisotropy (FA) was lower in Veterans with DEP compared to those without. These findings complement those observed in previous work on depression and support the hypothesis that the disruption of cortical-subcortical circuits may be involved in the etiology of depression. Notably, this is the first study to demonstrate the robustness of white matter abnormalities in DEP even in the presence of co-occurring PTSD and TBI.

Language: en