title: Predictors of Neurocognitive Syndromes in Combat Veterans.
abstract: Traumatic brain injury, depression and posttraumatic stress disorder (PTSD) are neurocognitive syndromes often associated with impairment of physical and mental health, as well as functional status. These syndromes are also frequent in military service members (SMs) after combat, although their presentation is often delayed until months after their return. The objective of this prospective cohort study was the identification of independent predictors of neurocognitive syndromes upon return from deployment could facilitate early intervention to prevent disability. We completed a comprehensive baseline assessment, followed by serial evaluations at three, six, and 12 months, to assess for new-onset PTSD, depression, or postconcussive syndrome (PCS) in order to identify baseline factors most strongly associated with subsequent neurocognitive syndromes. On serial follow-up, seven participants developed at least one neurocognitive syndrome: five with PTSD, one with depression and PTSD, and one with PCS. On univariate analysis, 60 items were associated with syndrome development at p < 0.15. Decision trees and ensemble tree multivariate models yielded four common independent predictors of PTSD: right superior longitudinal fasciculus tract volume on MRI; resting state connectivity between the right amygdala and left superior temporal gyrus (BA41/42) on functional MRI; and single nucleotide polymorphisms in the genes coding for myelin basic protein as well as brain-derived neurotrophic factor. Our findings require follow-up studies with greater sample size and suggest that neuroimaging and molecular biomarkers may help distinguish those at high risk for post-deployment neurocognitive syndromes.
authors.affiliation: Department of Medicine, Uniformed Services University of the Health Sciences.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Roy
authors.affiliation: Department of Medicine, Uniformed Services University of the Health Sciences.
authors.forename: Michelle
authors.initials: M
authors.lastname: Costanzo
authors.affiliation: National Institute of Nursing Research, National Institutes of Health.
authors.forename: Jessica
authors.initials: J
authors.lastname: Gill
authors.affiliation: Department of Medicine, Uniformed Services University of the Health Sciences.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Leaman
authors.affiliation: Traumatic Brain Injury Service, Walter Reed National Military Medical Center.
authors.forename: Wendy
authors.initials: W
authors.lastname: Law
authors.affiliation: National Intrepid Center of Excellence, Walter Reed National Military Medical Center.
authors.forename: Rochelle
authors.initials: R
authors.lastname: Ndiongue
authors.affiliation: Department of Medicine, Uniformed Services University of the Health Sciences.
authors.forename: Patricia
authors.initials: P
authors.lastname: Taylor
authors.affiliation: National Institute of Nursing Research , National Institutes of Health.
authors.forename: Hyung-Suk
authors.initials: HS
authors.lastname: Kim
authors.affiliation: RTI International.
authors.forename: Gayle S
authors.initials: GS
authors.lastname: Bieler
authors.affiliation: RTI International.
authors.forename: Nikhil
authors.initials: N
authors.lastname: Garge
authors.affiliation: Traumatic Injury Research Program, Uniformed Services University of the Health Sciences.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Rapp
authors.affiliation: Traumatic Injury Research Program, Uniformed Services University of the Health Sciences.
authors.forename: David
authors.initials: D
authors.lastname: Keyser
authors.affiliation: Traumatic Brain Injury Service, Uniformed Services University of the Health Sciences.
authors.forename: Dominic
authors.initials: D
authors.lastname: Nathan
authors.affiliation: Department of Surgery , Uniformed Services University of the Health Sciences.
authors.forename: Michael
authors.initials: M
authors.lastname: Xydakis
authors.affiliation: Image Processing Core, Center for Neuroscience and Regenerative Medicine, Henry Jackson Foundation.
authors.forename: Dzung
authors.initials: D
authors.lastname: Pham
authors.affiliation: Behavioral Neurology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health.
authors.forename: Eric
authors.initials: E
authors.lastname: Wassermann
keywords: biomarkers; combat military veterans; depression; neuroimaging; posttraumatic stress disorder; traumatic brain injury