post-traumatic flashback

   Also known as revisualization. In a broad sense, the term flashback has a bearing on any experiential phenomenon that may arise either in the context of post-traumatic stress disorder (PTSD) or as a consequence of the prior use of * hallucinogens. For the hallucinogen-related type of flashback, see the entry Flashback (drug related). In the literature on PTSD, the terms flashback and post-traumatic flashback are used to denote the * reperception (in most instances involving a revisualization) of a trauma scene, typically in the presence of a clear sensorium. These revisualizations tend to have a realistic intensity, and to be accompanied by a high level of emotional arousal (i.e. up to the equivalent of a panic attack). Post-traumatic flashbacks are often repetitive in nature. The affected individual may feel as if he or she is re-experiencing the prior trauma scene and lose touch with external reality. Post-traumatic flashbacks typically come and go, in the presence or absence of an environmental cue (such as a familiar smell, a violent movie scene, or the birth date of a deceased loved one) or an endogenous trigger (such as fatigue or pain). In susceptible individuals, they can be induced artificially with the aid of chemicals such as sodium lac-tate or a *deliriant. Qualitatively, post-traumatic flashbacks may range from 'image memories' or 'forced recollections' to * hallucinations proper, and the latter from * simple to * panoramic types of hallucinations. In some operational definitions the term post-traumatic flashback is stretched to include other PTSD symptoms as well, such as * nightmares, *hallucinoid experiences, * hypnagogic and * hypnopompic hallucinations, * illusions, and vivid * imagery. Post-traumatic flashbacks occurring in a different sensory modality (such as * olfactory flashbacks) have occasionally been reported. The pathophys-iology of post-traumatic flashbacks is basically unknown. It has been suggested that flashbacks may lie on a continuum with nightmares and other sleep-related disturbances, but empirical data suggest that * dream activity and flashback activity are mutually independent perceptual phenomena. Alternatively, it has been suggested that the occurrence of flashback phenomena may be associated primarily with ongoing daytime mental imagery, intensified under the influence of the affect. It has also been suggested that post-traumatic flashbacks may be related in a conceptual as well as a phenomenological sense (and perhaps also in a pathophysiological sense) with other mnestic events, such as drug-related flashbacks, * hallucinogen-induced persistent perception disorder (HPPD), *palinopsia, *reperceptive hallucinations, *phantom pain, *eidetic imagery, and * flashbulb memories. The term * projected flashback is sometimes used to denote a flashback of an injury beyond the one that actually occurred, as reported by postoperative patients with a clinical diagnosis of PTSD. The issue of whether flashbacks in the restricted sense should be conceptualized as veridical reperceptions, or perhaps as reconstructions - or even confabulations - accompanied by a *déjà vu-like sensation is as yet unsettled.

   References

   Burstein, A. (1985). Posttraumatic flashbacks, dream disturbances, and mental imagery. Journal ofClinical Psychiatry, 46, 374-378.

   Sierra, M., Berrios, G.E. (2000). Flashbulb and flashback memories .In: Memory disorders in psychiatric practice. Edited by Berrios, G.E., Hodges, J.R. Cambridge: Cambridge University Press.