Intimate partner violence perpetration among veterans: associations with neuropsychiatric symptoms and limbic microstructure.

Background: Intimate partner violence (IPV) perpetration is highly prevalent among veterans. Suggested risk factors of IPV perpetration include combat exposure, post-traumatic stress disorder (PTSD), depression, alcohol use, and mild traumatic brain injury (mTBI). While the underlying brain pathophysiological characteristics associated with IPV perpetration remain largely unknown, previous studies have linked aggression and violence to alterations of the limbic system. Here, we investigate whether IPV perpetration is associated with limbic microstructural abnormalities in military veterans. Further, we test the effect of potential risk factors (i.e., PTSD, depression, substance use disorder, mTBI, and war zone-related stress) on the prevalence of IPV perpetration.
Methods: Structural and diffusion-weighted magnetic resonance imaging (dMRI) data were acquired from 49 male veterans of the Iraq and Afghanistan wars (Operation Enduring Freedom/Operation Iraqi Freedom; OEF/OIF) of the Translational Research Center for TBI and Stress Disorders (TRACTS) study. IPV perpetration was assessed using the psychological aggression and physical assault sub-scales of the Revised Conflict Tactics Scales (CTS2). Odds ratios were calculated to assess the likelihood of IPV perpetration in veterans with either of the following diagnoses: PTSD, depression, substance use disorder, or mTBI. Fractional anisotropy tissue (FA) measures were calculated for limbic gray matter structures (amygdala-hippocampus complex, cingulate, parahippocampal gyrus, entorhinal cortex). Partial correlations were calculated between IPV perpetration, neuropsychiatric symptoms, and FA.
Results: Veterans with a diagnosis of PTSD, depression, substance use disorder, or mTBI had higher odds of perpetrating IPV. Greater war zone-related stress, and symptom severity of PTSD, depression, and mTBI were significantly associated with IPV perpetration. CTS2 (psychological aggression), a measure of IPV perpetration, was associated with higher FA in the right amygdala-hippocampus complex ( r  = 0.400, p  = 0.005).
Conclusion: Veterans with psychiatric disorders and/or mTBI exhibit higher odds of engaging in IPV perpetration. Further, the more severe the symptoms of PTSD, depression, or TBI, and the greater the war zone-related stress, the greater the frequency of IPV perpetration. Moreover, we report a significant association between psychological aggression against an intimate partner and microstructural alterations in the right amygdala-hippocampus complex. These findings suggest the possibility of a structural brain correlate underlying IPV perpetration that requires further research.
Competing Interests: IK is a professor at Ludwig-Maximilians-University Munich (paid position). She serves as European Editor at Journal of Neurotrauma (unpaid position) and as Vice President of the European Neurotrauma Organization (unpaid position). She receives research grant funding from the National Institutes of Health, the European Research Council, the German Ministry for Research and Education. She receives funding for a research study on sport-related concussion from Abbott Inc. The Ludwig-Maximilians-University hospital received donations for her research from the Schatt Foundation and from Mary Ann Liebert Inc. She receives royalties for book chapters published by Thieme Publishers. Her spouse is employee at Siemens and she thus holds stock options at Siemens and Siemens Healthineers. IK’s in-kind contributions: PhD students working under her supervision receive scholarships from the Villigst Foundation, the Konrad Adenauer Foundation, the Studienstiftung des deutschen Volkes, the China Scholarship Council collaboration with Ludwig-Maximilians-University Munich, the Harvard Munich Club, and Fulbright. MS is Professor of Psychiatry and Radiology at Harvard Medical School and is employed by Brigham and Women’s Hospital. She has grant funding from the National Institute of Mental Health and formerly from VA Merit Awards and from the National Institute of Neurological Diseases and Stroke. She serves on the editorial board of several professional journals (unpaid), on NIH study sections (Honoria minimum), and she receives royalties for book chapters and books published by Thieme Publishers, Elsevier, and Cambridge University Press (minimal). She receives funding also for legal cases as a consultant and an expert witness related to mild traumatic brain injury and the use of diffusion tensor imaging in the courtroom. MS’s in-kind contributions include PhD, MD, MD-PhD trainees and junior faculty working under her mentorship, many of whom have received K awards and grant support for their research. EK received speaker honoraria and financial compensation for travel expenses from Medtronic, UCB, Livanova, and Eisai and has participated in clinical trials for Medtronic, UCB and Precisis, all unrelated to the submitted work. Her research is supported by the Medical Clinical Scientist Program (MCSP). SH is a retired United States Army Medical Corps Officer. He is a consultant for the National Football League Players Association, Major League Soccer Players Association, SCS Consulting LLC. He is an advisory board member for the Project Enlist (Veterans Advisory Board of the Concussion Legacy Foundation), NanoDX, Prevent Biometrics, Owl Therapeutics Inc., University of Michigan Concussion Center, and Collaborative Neuropathology Network Characterizing Outcomes of TBI (CONNECT-TBI). He is a co-PI for the Long-term Impact of Military-relevant, Brain Injury Consortium – Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC). The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.
(Copyright © 2024 Rojczyk, Heller, Seitz-Holland, Kaufmann, Sydnor, Berger, Pankatz, Rathi, Bouix, Pasternak, Salat, Hinds, Esopenko, Fortier, Milberg, Shenton and Koerte.)