Most readers know that PTSD can be caused by intense trauma from accidents and injuries, but the question whether medical intervention itself can cause PTSD has not been extensively studied. Dr. Dimitry Davydow of the University of Washington’s School of Medicine reports in the Sept.-Oct. issue of General Hospital Psychiatry that as many as 22% of ICU patients will later suffer PTSD. This conclusion arose from the review of 15 medical studies and 1,745 ICU patients. The symptoms of PTSD include nightmares, sleep problems, flashbacks, irritability and anger, as well as emotional numbness. The risk of suffering PTSD increased if the patient had underlying mental illness, such as anxiety or depression, or was treated with certain sedatives that cause disorientation, confusion, or psychotic experiences.