CASP9 and post-traumatic stress disorder: In Past PTSD ≤ 5 y, high CASP-9 (12.3–35.05 ng/mL) indicates elevated apoptotic stress, likely driven by trauma-induced dysregulation, correlating with impaired adaptive coping (e.g., Problem-Focused: 10–16/32) and elevated avoidance (21–29/32).