Answer:
the necessary criterion to validate the diagnosis is "at least 1 month of clinically significant distress affecting a person after witnessing or experiencing a traumatic event that affects other parts of his or her life"
Step-by-step explanation:
posttramatic stress disorder (PTSD):"is a mental health condition that's triggered by a terrifying event — either experiencing it or witnessing it. Symptoms may include flashbacks, nightmares and severe anxiety, as well as uncontrollable thoughts about the event."