Investigating the neural network correlates of apathy, disinhibition, and executive dysfunction in active-duty United States Special Operations Forces

Natalie Gilmore^{1

2}, Isabella R McKinney^{1

2}, Chieh-En J Tseng³, Douglas N Greve³, Chiara Maffei^{1

2

3}, Brian C Healy^{2

4}, Nicole R Zürcher³, Jacob M Hooker³, Samantha L Tromly⁵, Daniel P Perl⁶, Kristen Dams-O'Connor⁷, Christine L Mac Donald⁸, Brian L Edlow^{1

2

3}, Yelena G Bodien^{9

10

11}

Affiliations

¹ Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital, Boston, MA, 02114, USA.
² Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA.
³ Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
⁴ Biostatistics Center, Massachusetts General Hospital, Boston, MA, 02114, USA.
⁵ Institute of Applied Engineering, University of South Florida, Tampa, FL, 33612, USA.
⁶ Department of Pathology, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD, 20814, USA.
⁷ Department of Rehabilitation and Human Performance, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
⁸ Department of Neurological Surgery, University of Washington, Seattle, WA, 98195, USA.
⁹ Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital, Boston, MA, 02114, USA. ybodien@mgh.harvard.edu.
¹⁰ Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA. ybodien@mgh.harvard.edu.
¹¹ Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, 02129, USA. ybodien@mgh.harvard.edu.

PMID: 40100566
DOI: 10.1007/s11682-025-00980-4

Investigating the neural network correlates of apathy, disinhibition, and executive dysfunction in active-duty United States Special Operations Forces

Natalie Gilmore et al. Brain Imaging Behav. 2025 Jun.

. 2025 Jun;19(3):627-636.

doi: 10.1007/s11682-025-00980-4. Epub 2025 Mar 18.

Authors

Affiliations

¹ Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital, Boston, MA, 02114, USA.
² Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA.
³ Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
⁴ Biostatistics Center, Massachusetts General Hospital, Boston, MA, 02114, USA.
⁵ Institute of Applied Engineering, University of South Florida, Tampa, FL, 33612, USA.
⁶ Department of Pathology, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD, 20814, USA.
⁷ Department of Rehabilitation and Human Performance, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
⁸ Department of Neurological Surgery, University of Washington, Seattle, WA, 98195, USA.
⁹ Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital, Boston, MA, 02114, USA. ybodien@mgh.harvard.edu.
¹⁰ Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA. ybodien@mgh.harvard.edu.
¹¹ Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, 02129, USA. ybodien@mgh.harvard.edu.

PMID: 40100566
DOI: 10.1007/s11682-025-00980-4

Abstract

United States Special Operations Forces (SOF) experience neurobehavioral symptoms that can adversely affect training and combat operations. Understanding the neurobiological basis for these symptoms may guide prevention and treatment. In 29 male active-duty SOF with mean (SD) 17(4) years of service, we tested whether self-reported symptoms of apathy, disinhibition, and executive dysfunction measured by the Frontal Systems Behavior Scale, were related to functional magnetic resonance imaging and positron emission tomography biomarkers (translocator protein and tau) of the limbic, salience, and executive control networks. Higher disinhibition was associated with lower functional connectivity and higher tau signal within the salience network, though both associations diminished with age. These findings provide the basis for future multimodal studies to elucidate the relationship between neurobehavioral symptoms and neuroimaging biomarkers in the context of repeated blast exposure.

Keywords: Blast injuries; Functional magnetic resonance imaging; Military personnel; Neurobehavioral symptoms; Positron emission tomography.

PubMed Disclaimer

Conflict of interest statement

Declarations. Disclaimer: The opinions and assertions expressed herein are those of the author(s) and do not reflect the official policy or position of the Uniformed Services University of the Health Sciences or the Department of Defense. Competing interests: The authors declare no competing interests.

References

1. Barczak-Scarboro, N. E., Cole, W. R., DeLellis, S. M., Means, G. E., Kane, S. F., Lynch, J. H., & Mihalik, J. P. (2020). Mental health symptoms are associated with mild traumatic brain injury history in active Special Operations forces (SOF) combat and combat support soldiers. Military Medicine, 185(11–12). e1946-e1953. https://doi.org/10.1093/milmed/usaa167
1. Bejanin, A., Schonhaut, D. R., La Joie, R., Kramer, J. H., Baker, S. L., Sosa, N., Ayakta, N., Cantwell, A., Janabi, M., Lauriola, M., O’Neil, J. P., Gorno-Tempini, M. L., Miller, Z. A., Rosen, H. J., Miller, B. L., Jagust, W. J., & Rabinovici, G. D. (2017). Tau pathology and neurodegeneration contribute to cognitive impairment in Alzheimer’s disease. Brain, 140(12), 3286–3300. https://doi.org/10.1093/brain/awx243 - DOI - PubMed - PMC
1. Benjamini, D., Priemer, D. S., Perl, D. P., Brody, D. L., & Basser, P. J. (2023). Mapping astrogliosis in the individual human brain using multidimensional MRI. Brain, 146(3), 1212–1226. https://doi.org/10.1093/brain/awac298 - DOI - PubMed
1. Berry, K. G., Sakallaris, B., & Deuster, P. A. (2019). Measuring Special Operations Forces readiness. Journal of Special Operations Medicine: A Peer Reviewed Journal for SOF Medical Professionals, 19(4), 100–104. https://doi.org/10.55460/MPAK-RB6Q
1. Betthauser, T. J., Cody, K. A., Zammit, M. D., Murali, D., Converse, A. K., Barnhart, T. E., Stone, C. K., Rowley, H. A., Johnson, S. C., & Christian, B. T. (2019). In vivo characterization and quantification of neurofibrillary Tau PET radioligand (18)F-MK-6240 in humans from Alzheimer disease dementia to young controls. Journal of Nuclear Medicine, 60(1), 93–99. https://doi.org/10.2967/jnumed.118.209650

MeSH terms

Actions
Actions
Actions
Actions
Actions
Actions
Actions
Actions
Actions
Actions
Actions
Actions
Actions
Actions
Actions
Actions
Actions
Actions

Substances

Actions

Grants and funding

H9240520D0001/U.S. Department of Defense

LinkOut - more resources

Full Text Sources
- Springer
Medical
- MedlinePlus Health Information
Research Materials
- NCI CPTC Antibody Characterization Program

Save citation to file

Email citation

Add to Collections

Add to My Bibliography

Your saved search

Create a file for external citation management software

Your RSS Feed

Investigating the neural network correlates of apathy, disinhibition, and executive dysfunction in active-duty United States Special Operations Forces

Affiliations

Investigating the neural network correlates of apathy, disinhibition, and executive dysfunction in active-duty United States Special Operations Forces

Authors

Affiliations

Abstract

Conflict of interest statement

References

MeSH terms

Substances

Grants and funding

LinkOut - more resources

Full Text Sources

Medical

Research Materials