TBI is a major population health concern in U.S. service members and Veterans. Research has shown that Veterans who sustain the most common form of TBI, mild TBI (mTBI, or concussion), often report varied and lasting neurobehavioral complaints and functional impairments, placing them at-risk for long-term disability. Other factors, such as distress brought about by co-occurring mental health conditions and chronic pain, are thought to contribute to these negative outcomes, and recent studies have shown that mental health intervention can improve neurobehavioral functioning in these Veterans. However, barriers to accessing effective mental health care are evident. For instance, many mental health treatments require a high time and resource investment for both patients and providers, and many mTBI-focused treatments are only accessible in specialty treatment environments. Further, interventions capable of addressing the variety of neurobehavioral complaints cited in this clinical cohort are lacking. To address these gaps in care, our team recently adapted Problem-Solving Training for Concussion (PST-Concussion), a brief, primary care-based cognitive-behavioral intervention designed to improve recovery from mTBI. PST-Concussion was specifically adapted for use in the primary care setting given its practical advantages for easy access to care, and the emphasis on primary care management present in current mTBI clinical practice guidelines. While our preliminary work established that PST-Concussion is acceptable and feasible, a more comprehensive evaluation is needed to determine whether it is clinically effective. To this end, the proposed study will be a longitudinal randomized two-arm parallel group clinical trial. One hundred thirty-four participants will be randomized 1:1 to either PST- Concussion or treatment as usual (TAU). Eligible participants will be Veterans ages 18 and older who are enrolled in Veterans Health Administration (VHA) care and evidence: a) history of mTBI; b) current psychological distress; and c) persistent neurobehavioral symptoms of ≥ 3 months. Participants assigned to PST-Concussion will receive six, approximately 30-minute telehealth treatment sessions. Sessions include standard concussion education, motivational interviewing and goal-setting, compensatory cognitive strategies, relaxation training, and training in planful problem-solving. Assessments will include standard self-report and cognitive measures that will be administered at baseline, post-treatment, and three-month follow-up. The primary objective of this study will be to evaluate the effectiveness of PST-Concussion in reducing psychological distress compared to TAU. Secondary and tertiary objectives will be to evaluate whether PST- Concussion is associated with appreciable change in subjective neurocognitive functioning, objective neurocognitive functioning, psychosocial functioning, and disability and quality of life. Multi-level modeling will be used to eval...