Veteran's Interdisciplinary Care for Traumatic Brain Injury and Co-Occurring Disorders Rehabilitation Trial

The goal of this clinical trial is to learn if the Avalon Action Alliance Interdisciplinary Outpatient Rehabilitation Program (IORP) can reduce long-lasting symptoms of traumatic brain injury (TBI) and co-occurring disorders in veterans and first responders. The main questions it aims to answer are: * Does a 3-week IORP reduce symptoms of long-lasting TBI and co-occurring disorders in military veterans and first responders? * Does the 3-week IORP improve life quality and function in military veterans and first responders? Researchers will compare the Control group to the Invention group to see if a 3-week of IORP reduced symptoms of TBI and co-occurring disorders in military veterans and first responders. Participants will complete the following activities. The items with an asterisk(\*) are not required or available at all sites. * Answer online survey questions about their TBI symptoms, life satisfaction, and life activities * Complete two blood draws\* * Complete two magnetic resonance imaging (MRI) brain scans\*