The Translational Research Center for TBI and Stress Disorders (TRACTS, funded initially in 2009), a VA RR&D TBI National Network Research Center based at the VA Boston Healthcare System, with a network site at the Michael E. DeBakey VA Medical Center, intends to continue its mission of conducting multidisciplinary, clinical research aimed at providing a multimodal psychological, biological, and neurobiological characterization of traumatic brain injury (TBI) and deployment related stress disorders, and to use this understanding to improve treatment for Veterans in the post-9/11 era, and ultimately for the entire population served by the VHA. Taking a lifespan developmental approach, our carefully characterized and curated cohort will continue to provide a wealth of insight into the complex medical and psychological problems besetting the veterans who have entrusted us with their care. We identify four primary areas of scientific focus for TRACTS over the next funding cycle, 2024-2029. There are a number of new projects proposed within each focus area: Focus Area 1: Deep phenotyping of deployment trauma and its functional consequences using symptom- based clinical presentations, molecular, genetic, and neurobiological advances from TRACTS – understanding longitudinal pathways and trajectories to predict outcome. This central focus around investigative studies concerned with the diagnosis and characterization of TBI, particularly concussion or mTBI as it occurs in the context of other common deployment related comorbidities, such as PTSD, will continue leveraging newly available longitudinal data. Focus Area 2: Molecular and neurobiological characterization of deployment related brain trauma using neuroimaging has been a central focus of TRACTS from its inception. Over the last decade we have developed increasingly sophisticated approaches to study how the central nervous system is impacted by TBI and its deployment related comorbidities in veterans. In the next funding period, we will have access to a newly purchased Prisma 3T scanner, which will largely be devoted to research at VA Boston, that will greatly accelerate our ability to develop new techniques in both functional and structural neuroimaging (e.g., adapting proton density scans to examine the details of limbic and brain stem circuits, co-registration of EEG and MRI data, MR Spectography, etc.). We will also add more sophisticated approaches to the analysis of MRI based data in relationship to genomic and phenomic data from the TRACTS Longitudinal Cohort (TLC). Focus Area 3: We will continue to develop innovative rehabilitative strategies to alleviate the physical and psychological symptoms of veterans and to gain a more thorough understanding of the mechanisms of treatment effectiveness. Of paramount importance to the TRACTS mission is to utilize the knowledge that has been gained from the TLC to create or adapt treatment models to better support veterans’ reintegration and adjustment ...