Requires the Department of Veterans Affairs to carry out a multi‑site study using RNA sequencing to evaluate whether markers of inflammation or cellular stress can help diagnose veterans who show symptoms of post‑traumatic stress disorder (PTSD). The study must begin within 120 days of enactment, run in VA medical facilities across five Veterans Integrated Service Networks, end on September 30, 2027, and the VA must deliver a report of findings to the House and Senate Veterans’ Affairs Committees by September 30, 2028.