NOS1 and post-traumatic stress disorder: Clinically, elevated nNOS levels in PTSD patients, particularly in the chronic phase (>5 y), impair adaptive coping (Problem-Focused and Emotion-Focused) and overall coping capacity, reflecting persistent oxidative stress and potential exacerbation of psychiatric symptoms such as hyperarousal (DSM-5 Criterion E) and negative alterations in cognition (Criterion D).