A DSM-5 diagnosis involving five diagnostic criteria: exposure to a traumatic event (e.g., sexual assault); presence of at least 9 of 14 symptoms from among five symptom categories (intrusion, negative mood, dissociative, avoidance, and arousal); duration of symptoms is 3 days to 1 month after exposure; clinically significant distress or impairment in functioning; and, symptoms are not substance induced or secondary to another medical condition. Persistent symptoms beyond one month may indicate progression to PTSD.