identity disorder, elevated or depressed mood  may be displayed in conjunction with overt
identities, so one or the other mood may pred ominate for a relatively  long period of time
(often for days) or may shift within minutes.
Posttraumatic stress disorder. Some traumatized individua ls have both posttraumatic
stress disorder (PTSD) and dissociative identity disorder. Accordingly, it is crucial to dis-
tinguish between individuals with PTSD only an d individuals who have both PTSD and
dissociative identity disorder. This different ial diagnosis requires that the clinician estab-
lish the presence or absence of dissociative sy mptoms that are not characteristic of acute
stress disorder or PTSD. Some individuals wi th PTSD manifest diss ociative symptoms that
also occur in dissociative identity disorder: 1) amnesia for some aspe cts of trauma, 2) dis-
sociative flashbacks (i.e., reliving of the trauma, with reduced awareness of one’s current
orientation), and 3) symptoms of intrusion an d avoidance, negative alterations in cogni-
tion and mood, and hyperarousal that are focu sed around the traumatic event. On the other
hand, individuals with dissociative identity disorder manifest dissociative symptoms that
are not a manifestation of PTSD: 1) amnesias for many everyday (i.e., nontraumatic) events,
2) dissociative flashbacks that may be followe d by amnesia for the content of the flashback,
3) disruptive intrusions (unrelated to trau matic material) by dissociated identity states
into the individual’s sense of self and agency, and 4) infrequent, full-blown changes
among different identity states.
Psychotic disorders. Dissociative identity disorder may be confused with schizophre-