The Precision Brain Health Research Act of 2025 modifies the Department of Veterans Affairs' Precision Medicine for Veterans Initiative, expanding its focus to include repetitive low-level blast exposure and dementia , alongside other brain and mental health conditions. This aims to better address a broader range of neurological and psychological challenges faced by veterans. A key provision establishes a data-sharing partnership between the Department of Veterans Affairs and the Department of Defense, integrating relevant military data onto an open platform. The bill mandates extensive research into low-level blast injuries, including big-data assessments, large-scale implementation studies of interventions, translational research on growth hormone replacement therapy, and quality improvement studies for diagnosis and care. Additionally, the legislation requires the VA Secretary to contract with the National Academies of Sciences, Engineering, and Medicine to validate brain and mental health biomarkers among veterans, with biennial reports to Congress. It also mandates regular assessments of research studies and biennial reports to Congress on the initiative's progress and recommendations. The bill authorizes an appropriation of $5,000,000 annually for the initiative from fiscal years 2025 through 2034 to support these expanded efforts.