Combat Dementia in Military Personnel: A Novel Neurocognitive Profile of Relentless War

Combat Dementia in Military Personnel: A Novel Neurocognitive Profile of Relentless War | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Combat Dementia in Military Personnel: A Novel Neurocognitive Profile of Relentless War Oleksandr Kulyk, Olena Maidannyk This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7166620/v3 This work is licensed under a CC BY 4.0 License Status: Under Review Version 3 posted 6 You are reading this latest preprint version Show more versions Abstract We introduce the term "combat dementia" as a novel neurocognitive phenotype that emerges in military personnel as a consequence of prolonged and continuous exposure to combat environments. In a prospective cohort (2014–2025; n = 297), neuropsychological testing (MoCA), cognitive event-related potentials, quantitative EEG, and multidisciplinary clinical evaluation were performed. Three phenotypes of cognitive impairment were distinguished for clinical analysis: (A) post-traumatic brain injury (TBI) with MRI/CT-verified macrostructural changes (classical organic variant); (B) without TBI and PTSD, with no macrostructural alterations on MRI/CT, but with persistent network-level microstructural pathology verified by specific neurophysiological markers (persistent variant, i.e., "combat dementia"); (C) associated with PTSD/cumulative psychotrauma, without neuroimaging evidence of macrostructural lesions or neurophysiological indicators of stable microstructural pathology, but with predominantly functional changes verified by neurophysiological markers and potentially reversible dynamics (transitional/borderline variant). Three distinct trajectories of cognitive decline were identified: macrostructural organic (A), microstructural persistent (B), and transitional/borderline (C). Phenotype C, occupying an intermediate position between A and B, illustrates a possible transformation from functional network-level alterations to stable microstructural pathology, thereby explaining the increased risk of dementia in cases of chronic PTSD. Key predictors of accelerated decline included age and continuous frontline exposure exceeding 14 months, which was associated with nearly a threefold increase in the risk of progression to more severe stages of cognitive impairment. Summarized longitudinal observations (6/12 months; subgroups of 3–10 years) confirm the stability of phenotype B and its distinction from phenotypes A and C; an extended analysis will be presented in subsequent publications. Recognition of combat dementia as an independent clinical entity is critically important for the development of new screening strategies, rehabilitation programs, and nosological classification of cognitive disorders in military populations. The findings delineate a novel domain in neuropsychiatry, with implications not only for Ukraine but also for the international community in shaping humanitarian and social policy, as well as rehabilitation systems and military medical expertise. Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 3 posted Reviews received at journal 10 Mar, 2026 Reviewers agreed at journal 02 Mar, 2026 Reviewers invited by journal 20 Feb, 2026 Editor assigned by journal 13 Feb, 2026 Submission checks completed at journal 22 Nov, 2025 First submitted to journal 22 Nov, 2025 You are reading this latest preprint version Show more versions Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7166620","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[{"code":1,"date":"2025-08-11 05:37:38","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research 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In a prospective cohort (2014–2025; n = 297), neuropsychological testing (MoCA), cognitive event-related potentials, quantitative EEG, and multidisciplinary clinical evaluation were performed. Three phenotypes of cognitive impairment were distinguished for clinical analysis:\n(A) post-traumatic brain injury (TBI) with MRI/CT-verified macrostructural changes (classical organic variant);\n(B) without TBI and PTSD, with no macrostructural alterations on MRI/CT, but with persistent network-level microstructural pathology verified by specific neurophysiological markers (persistent variant, i.e., \"combat dementia\");\n(C) associated with PTSD/cumulative psychotrauma, without neuroimaging evidence of macrostructural lesions or neurophysiological indicators of stable microstructural pathology, but with predominantly functional changes verified by neurophysiological markers and potentially reversible dynamics (transitional/borderline variant).\nThree distinct trajectories of cognitive decline were identified: macrostructural organic (A), microstructural persistent (B), and transitional/borderline (C). Phenotype C, occupying an intermediate position between A and B, illustrates a possible transformation from functional network-level alterations to stable microstructural pathology, thereby explaining the increased risk of dementia in cases of chronic PTSD. \nKey predictors of accelerated decline included age and continuous frontline exposure exceeding 14 months, which was associated with nearly a threefold increase in the risk of progression to more severe stages of cognitive impairment. Summarized longitudinal observations (6/12 months; subgroups of 3–10 years) confirm the stability of phenotype B and its distinction from phenotypes A and C; an extended analysis will be presented in subsequent publications. \nRecognition of combat dementia as an independent clinical entity is critically important for the development of new screening strategies, rehabilitation programs, and nosological classification of cognitive disorders in military populations. 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