Snapshot A 22-year-old young man presents to your clinic claiming that he has not been himself lately. He just returned from his service in the military where several of his comrads were killed and he was sexually abused by a superior officer. Since then his personality has had a more flat affect and his girlfriend admits to gaps in his memory both of the event and since the event. At times during your interview with this patient you note he seems to not be paying attention or truly present in the conversation. The patient denies suicidal ideation. Overview Dissociation temporary alteration in any combination of the following to deal with emotional stress memory personality consciousness motor behavior can progress to multiple personality disorder Dissociative identity disorder presence of 2 or more distinct identities or personality states that recurrently take control of behavior gaps in recall for traumatic or everyday events formerly known as multiple personality disorder more common in women associated with a history of sexual abuse, PTSD, depression, borderline personality disorder, substance abuse, somatoform conditions Depersonalization/derealization disorder (new designation in DSM-V) persistent feelings of detachment or estrangement from oneself (depersonalization) environement (derealization) Dissociative amnesia inability to recall personal information typically secondary to stress or trauma dissociative fugue - a progression of dissociative amnesia abrupt change in geographic location with inability to recall past and loss of identity associated with traumatic circumstances (e.g., disaster and war) leads to significant distress or impairment not the result of substance abuse or general medical condition