<prompt> Post-traumatic stress disorder is characterized by all ExceptFlash back and night mareSevere traumatic life eventRe-experiencing stressful eventsIt develops after 6 months of stress  <response>: Symptoms of PTSD develop within 6 months of stressor, however, 10 of patients have delayed the onset Reference: Kaplon and sadock, 11 th edition, synopsis of psychiatry, 11 th edition, pg no. 437 