It is increasingly recognized that returning Veterans and Service Members of Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) suffer from co-occurring psychological and physical conditions that produce complex patterns of cognitive, psychological, and physical symptoms that impede reintegration and make efficient and effective treatment planning difficult, if not impossible. Preliminary findings from our laboratory based on the analyses of two existing databases supports the idea that some patterns of co-occurring symptoms or diagnoses that include a history of mTBI are predictive of poor functional outcome, even more so than the effects of any individual diagnostic category including mTBI itself. Using factor analysis we have empirically identified three injury profiles that may represent biologically relevant unique clinical phenotypes related to deployment trauma. Using the TRACTS data repository, the first profile consists of PTSD, Major Depressive Disorder (MDD) with a history of mTBI, and we have called this the Deployment Trauma Phenotype (DTP). We have have shown that DTP is more predictive of substantial disability than other potential combinations of common diagnoses. Further preliminary evidence indicates that DTP may have a unique neural signature evident on high-resolution diffusion weighted neuroimaging. We have also identified two other prevalent coherent patterns of diagnoses: PTSD with Major Depression (PTSD/MDD) and mTBI with co-occurring pain and sleep disorder (somatic mTBI). In the current application, we proposed to use the TRACTS data repository to further examine the underlying neurologic basis and functional impact of the injury profiles we have defined (DTP, somatic mTBI, and PTSD/MD). This dataset will allow us to examine patient characteristics at longer time frames after TBI, as all TRACTS participants are assessed months to years following TBI. We also propose to examine the prevalence and functional outcome (employment, healthcare utilization) of these profiles using the TBI national dataset. This proposal will, for the first time, combine the advantages of a tightly managed and sophisticated cohort- based database (TRACTS data repository) and a much larger population-based medical database (TBI national database) to test and validate hypotheses about the effects of multiple deployment trauma based pathologies. It represents the first attempt to apply the whole brain morphometry-based multivariate modeling approaches to the question of differentiating potential biomarkers associated with deployment trauma based clinical phenotypes.
It is now recognized that returning Veterans and Service Members of Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) suffer from many psychological and physical conditions that may all occur in one individual. Studies so far suggest that certain combinations of diagnoses are likely to be the most disabling, and may be related to very specific changes in the brain. In the proposed work we will use two existing databases to investigate how having more than one trauma related diagnosis at a time can produce disability, and changes in the brain.
