Posttraumatic Stress Disorder is a disorder produced by exposure to an overwhelming environmental stress and characterized by recurrent episodes of reexperiencing the trauma.

This may occur in the form of dissociated states in which the patient appears to relive the stressful experience as if it were actually taking place.

Other episodes in Posttraumatic Stress Disorder are uncontrollable nightmares reproducing the traumatic events.

(Edited by Dr. María Moya Guirao, MD)