RecruitingDevice studyImproving Cognitive Rehabilitation OutcomesPosttraumatic stress disorder (PTSD) and mild TBI (mTBI) frequently co-occur in post-9/11 Veterans, and together are associated with worse cognitive performance, mental health, everyday functioning, community integration, quality of life, and treatment response than either condition alone. Additional comorbidities, such as depression and sleep disturbance, are common and further exacerbate these problems. The investigators will investigate Compensatory Cognitive Training (CCT) and Morning Bright Light Therapy (MBLT) vs Negative Ion Generator (ION), to directly target cognition, depression, and sleep disturbance and to improve CCT-associated rehabilitation outcomes. The investigator's randomized controlled trial in 144 Veterans with mTBI+PTSD across two VA sites will compare cognition, functioning, and other secondary outcomes following CCT+MBLT vs. CCT+ION. This study addresses the significant gap in services and evidence-based treatments for Veterans with mTBI+PTSD.