CASP9 and post-traumatic stress disorder: In contrast, Past PTSD ≤ 5 y patients exhibit elevated CASP-9 (12.3–35.05 ng/mL), low adaptive coping (Problem-Focused: 10–16/32; Emotion-Focused: 20–33/48), and high avoidance (21–29/32), reflecting a disrupted equilibrium due to acute trauma.