This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neurotic, Stress Related and Somatoform Disorders, Subject name: Psychiatry
Which of the following features is not characteristic of PTSD? 
Select and explain. 
A. Delusion, B. Night mares, C. Avoidance, D. Flashbacks
A: Delusion
Answer: A: Delusion 
Explanation: Diagnosing Post-traumatic Stress disorder: Atleast one month of the following 4 characteristic symptoms after a life-threatening experience: Night mares Hyper-arousal Flash backs Avoidance Late onset PTSD is symptoms appearing 6 months after the life-threatening event.