Recovered memory: Difference between revisions

From Citizendium
Jump to navigation Jump to search
imported>Gareth Leng
imported>Gareth Leng
Line 55: Line 55:


==Neurological Basis of Memory==
==Neurological Basis of Memory==
The neuroscientist [[Donald Hebb]] (1904 - 1985) was the first to distinguish between [[short-term memory]] and [[long-term memory]]. According to current theories in neuroscience, things that we "notice" are stored in short-term memory for up to a few minutes; this memory depends on 'reverberating' electrical activity in neuronal circuits, and is very easily destroyed by interruption or interference. Memories stored for longer than this are stored in ''long-term memory''. Whether information is stored in long-term memory depends on its 'importance'; for any animal, memories of traumatic events are potentially important for the adaptive value that they have for future avoidance behaviour, and [[hormones]] that are released during stress have a role in determining what memories are preserved. In humans, traumatic stress is associated with acute secretion of [[epinephrine]] and [[norepinephrine]] (adrenaline and noradrenaline) from the [[adrenal medulla]] and [[cortisol]] from the [[adrenal cortex]]. Increases in these facilitate memory, but chronic stress associated with prolonged hypersecretion of cortisol may have the opposite effect. The [[limbic system]], is involved in memory storage and retrieval as well as giving emotional significance to sensory inputs. Wihin the limbic system, the [[hippocampus]] is important for [[explicit memory]], and for [[memory consolidation]]; it is also sensitive to stress hormones, and has a role in recording the emotions of a stressful event. The [[amygdala]] may be particularly important in assigning emotional values to sensory inputs.
The neuroscientist [[Donald Hebb]] (1904 - 1985) was the first to distinguish between [[short-term memory]] and [[long-term memory]]. According to current theories in neuroscience, things that we "notice" are stored in short-term memory for up to a few minutes; this memory depends on 'reverberating' electrical activity in neuronal circuits, and is very easily destroyed by interruption or interference. Memories stored for longer than this are stored in ''long-term memory''. Whether information is stored in long-term memory depends on its 'importance'; for any animal, memories of traumatic events are potentially important for the adaptive value that they have for future avoidance behaviour, and [[hormones]] that are released during stress have a role in determining what memories are preserved. In humans, traumatic stress is associated with acute secretion of [[epinephrine]] and [[norepinephrine]] (adrenaline and noradrenaline) from the [[adrenal medulla]] and [[cortisol]] from the [[adrenal cortex]]. Increases in these facilitate memory, but chronic stress associated with prolonged hypersecretion of cortisol may have the opposite effect. The [[limbic system]], is involved in memory storage and retrieval as well as giving emotional significance to sensory inputs. Wihin the limbic system, the [[hippocampus]] is important for [[explicit memory]], and for [[memory consolidation]]; it is also sensitive to stress hormones, and has a role in recording the emotions of a stressful event. The [[amygdala]] may be particularly important in assigning emotional values to sensory inputs.<ref>Zola SM (1998) Memory, amnesia, and the issue of recovered memory: neurobiological aspects. ''Clin Psychol Rev'' 18:915-32. PMID 9885767 </ref>


==Amnesia==
==Amnesia==

Revision as of 05:42, 27 April 2009

This article is developing and not approved.
Main Article
Discussion
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
 
This editable Main Article is under development and subject to a disclaimer.

Template:TOC-right

Recovered memory is the description given to the apparent resurrection of the memory of events that had been forgotten or suppressed for a relatively long time. Retrograde amnesia secondary to physical or emotional trauma (i.e., traumatic amnesia), or the suppression of painful memories from any cause, is an accepted concept. But the mechanisms that lead to such reports are not well understood, and the authenticity of recovered memories has often been challenged; in some cases recovered memories are fictitious, although in other cases they may, apparently, be authentic and have been corroborated.[1] [2]

The issues surrounding recovered, or false memories have sparked one of the greatest controversies in the mental health profession of recent times.[3] Some researchers have proposed that memories of extreme trauma are buried in the subconscious by a special process, and are later reliably recovered. Others, consider that genuinely traumatic events are seldom truly forgotten, and that the scientific evidence indicates that traumatic amnesia is a myth.[4] However, traumatized individuals exhibit a range of memory impairments, and research on children's and adults' encoding and memory of trauma stimuli has provided preliminary support for models of repression and traumatic amnesia.[5]

Authenticity

Our memories can be accurate, but they are not always accurate. For example, eyewitness testimony even of relatively recent dramatic events is notoriously unreliable. [6] Misremembering results from confusion between memories for perceived and imagined events, which may result from overlap between particular features of the stored information comprising memories for perceived and imagined events. Our memories of events are always a mix of factual traces of sensory information overlaid with emotions, mingled with interpretation and "filled in" with imaginings. Thus there is always skepticism about how valid a memory is as evidence of factual detail. Some believe that accurate memories of traumatic events are often repressed, but remain in the subconscious mind, from where they can be recovered by appropriate therapy. Others believe that truly traumatic events are never forgotten in this way, although often people may not disclose their memories to others. This is a difficult area to study, and unambiguous conclusions are hard to draw, hence there continue to be very divergent opinions. In one study where victims of documented child abuse were reinterviewed many years later as adults, a high proportion of the women denied any memory of the abuse.[7]

Those who doubt the existence of "traumatic amnesia" note that various manipulations can be used to implant false memories (sometimes called "pseudomemories"). These can be quite compelling for those who develop them, and can include details that make them seem credible to others.[8] A classic experiment in memory research, conducted by Elizabeth Loftus, became widely known as "Lost in the Mall"; in this, subjects were given a booklet containing three accounts of real childhood events written by family members and a fourth account of a wholly fictitious event of being lost in a shopping mall. A quarter of the subjects reported remembering the fictitious event, and elaborated on it with extensive circumstantial detail.[9] This experiment inspired many others, and in one of these, Porter et al. could convince about half of his subjects that they had survived a vicious animal attack in childhood.[10]

Such experimental studies have been criticized [11] in particular about whether the findings are really relevant to trauma memories and psychotherapeutic situations.[12] [11] Nevertheless, these studies prompted public and professional concern about recovered memory therapy for past sexual abuse. When memories are 'recovered' after long periods of amnesia, particularly when extraordinary means were used to secure the recovery of memory, it is now widely (but not universally) accepted that the memories are quite likely to be false, i.e. of incidents that had not occurred.[13] It is thus recognised by professional organizations that a risk of implanting false memories is associated with some types of therapy. The American Psychiatric Association advises that "...most leaders in the field agree that although it is a rare occurrence, a memory of early childhood abuse that has been forgotten can be remembered later. However, these leaders also agree that it is possible to construct convincing pseudomemories for events that never occurred. The mechanism(s) by which both of these phenomena happen are not well understood and, at this point it is impossible, without other corroborative evidence, to distinguish a true memory from a false one." [14] [15]

Obviously, not all therapists agree that false memories are a major risk with psychotherapy and they argue that this idea overstates the data and is untested. [16] [17] Indeed some believe that memories recovered during psychotherapy are likely to be accurate, and several studies have reported that evidence supporting such recovered memories were found in many instances.[18][19] Several studies have reported high percentages of the corroboration of recovered memories.[20][21] Some authors have claimed that the false memory movement has a "tendency to conceal or omit evidence of (the) corroboration" of recovered memories.[22] Herman in her theory of recovery from Chronic Post-Traumatic Stress Disorder (C-PTSD) writes that one of the major recovery stages from C-PTSD is the remembering and mourning of the repressed material of traumatic events.[23][24]

Both true and false 'memories' can be recovered using memory work techniques, but there is no evidence that reliable discriminations can be made between them. [25] Some believe that memories "recovered" under hypnotism are particularly likely to be false. [26] According to The Council on Scientific Affairs for the American Medical Association, recollections obtained during hypnosis can involve confabulations and pseudomemories and appear to be less reliable than nonhypnotic recall. [27] Brown et al. estimate that 3 to 5% of laboratory subjects are vulnerable to post-event misinformation suggestions. They state that 5 - 8% of the general population is the range of high-hypnotizability. Twenty-five percent of those in this range are vulnerable to suggestion of psuedomemories for peripheral details, which can rise to 80% with a combination of other social influence factors. They conclude that the rates of memory errors run 0 - 5% in adult studies, 3 - 5% in children's studies and that the rates of false allegations of child abuse allegations run 4 - 8% in the general population [16].

Medico-Legal issues

Serious issues arise when recovered but false memories result in public allegations; false complaints carry serious consequences for the accused. Many of those who make false claims sincerely believe the truth of what they report. A special type of false allegation, the false memory syndrome, arises typically within therapy, when people report the 'recovery' of childhood memories of previously unknown abuse. The influence of practitioners' beliefs and practices in the eliciting of false 'memories' and of false complaints has come under particular criticism.[28] Sometimes these memories are used as evidence in criminal prosecutions.

It is generally accepted that people sometimes are unable to recall traumatic experiences. The current version (DSM-IV) of the Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association, states in section 300.12: "Dissociative amnesia is characterized by an inability to recall important personal information, usually of a traumatic or stressful nature, that is too extensive to be explained by ordinary forgetfulness."[29] The term "recovered memory", however, is not listed in DSM-IV or used by any mainstream formal psychotherapy modality.[30]

Alan Scheflin, a law professor, explains that this satisfies courts that recovered memories are admissible into evidence in court. "Both those who argue that repressed memories are always false and those who argue that repressed memories are always true [...] appear to be mistaken. Although the science is limited on this issue, the only three relevant studies conclude that repressed memories are no more and no less accurate than continuous memories....”[31] A U.S. District Court accepted repressed memories as admissible evidence in a specific case.[32] Dalenberg argues that the evidence shows that recovered memory cases should be allowed to be prosecuted in court[19]. The apparent willingness of courts to credit the recovered memories of complainants but not the absence of memories by defendents has been commented on "It seems apparent that the courts need better guidelines around the issue of dissociative amnesia in both populations."[33]

Neurological Basis of Memory

The neuroscientist Donald Hebb (1904 - 1985) was the first to distinguish between short-term memory and long-term memory. According to current theories in neuroscience, things that we "notice" are stored in short-term memory for up to a few minutes; this memory depends on 'reverberating' electrical activity in neuronal circuits, and is very easily destroyed by interruption or interference. Memories stored for longer than this are stored in long-term memory. Whether information is stored in long-term memory depends on its 'importance'; for any animal, memories of traumatic events are potentially important for the adaptive value that they have for future avoidance behaviour, and hormones that are released during stress have a role in determining what memories are preserved. In humans, traumatic stress is associated with acute secretion of epinephrine and norepinephrine (adrenaline and noradrenaline) from the adrenal medulla and cortisol from the adrenal cortex. Increases in these facilitate memory, but chronic stress associated with prolonged hypersecretion of cortisol may have the opposite effect. The limbic system, is involved in memory storage and retrieval as well as giving emotional significance to sensory inputs. Wihin the limbic system, the hippocampus is important for explicit memory, and for memory consolidation; it is also sensitive to stress hormones, and has a role in recording the emotions of a stressful event. The amygdala may be particularly important in assigning emotional values to sensory inputs.[34]

Amnesia

Amnesia is partial or complete loss of memory that goes beyond mere forgetting. Often it is temporary and involves only part of a person's experience. Amnesia is often caused by an injury to the brain, for instance after a blow to the head, and sometimes by psychological trauma. Anterograde amnesia is a failure to remember new experiences that occur after damage to the brain; retrograde amnesia is the loss of memories of events that occurred before a trauma or injury. For a memory to become permanent (consolidated), there must be a persistent change in the strength of connections between particular neurons in the brain. Anterograde amnesia can occur because this consolidation process is disrupted; retrograde amnesia can result either from damage to the site of memory storage or from a disruption in the mechanisms by which memories can be retrieved from their stores. Many specific types of amnesia are recognised, including:

  • Infantile (childhood) amnesia, the normal inability to recall events from early childhood. There are various theories about this; some believe that language development is important for efficient storage of long term memories, some believe that early memories do not persist because the brain is still developing.
  • Hysterical amnesia (dissociative Fugue or fugue amnesia), a rare condition linked to severe psychological trauma. It is characterised by epidode(s) of "an inability to recall some or all of one's past and either the loss of one's identity or the formation of a new identity occur with sudden, unexpected, purposeful travel away from home." Usually, the memory returns within a few days, although memory of the trauma may remain incomplete.

The form of amnesia that is linked with recovered memories is dissociative amnesia (formerly known as psychogenic amnesia). This is amnesia that results from a psychological cause, not by direct damage to the brain, and is a loss of memory of significant personal information, usually about traumatic or extremely stressful events. Usually this is seen as a gap or gaps in recall for aspects of someone's life history, but with severe acute trauma, such as during wartime, there can be a sudden acute onset of symptoms [35]

Effects of trauma on memory

'Betrayal Trauma Theory' proposes that in cases of childhood abuse, dissociative amnesia is an adaptive response , and that “victims may need to remain unaware of the trauma not to reduce suffering but rather to promote survival.”[36] When stress interferes with memory, it is possible that some of the memory is kept by a system that records emotional experience, but there is no symbolic placement of it in time or space.[37] Traumatic memories are retrieved, at least at first, in the form of dissociated mental imprints of the affective and sensory elements of the traumatic experience. Clients have reported the slow emergence of a personal narrative that can be considered explicit (conscious) memory.

Psychiatrist Bessel van der Kolk [21] divided the efffects of traumas on memory functions into four sets

  • traumatic amnesia; this involves the loss of memories of traumatic experiences. The younger the subject and the longer the traumatic event is, the greater the chance of significant amnesia. He stated that subsequent retrieval of memories after traumatic amnesia is well documented in the literature, with documented examples following natural disasters and accidents, in combat soldiers, in victims of kidnapping, torture and concentration camp experiences, in victims of physical and sexual abuse, and in people who have committed murder.
  • global memory impairment; this makes it difficult for subjects to construct an accurate account of their present and past history. "The combination of lack of autobiographical memory, continued dissociation and of meaning schemes that include victimization, helplessness and betrayal, is likely to make these individuals vulnerable to suggestion and to the construction of explanations for their trauma-related affects that may bear little relationship to the actual realities of their lives"
  • dissociative processes; this refers to memories being stored as fragments and not as unitary wholes.
  • traumatic memories’ sensorimotor organization. Not being able to integrate traumatic memories seems to be linked to post traumatic stress disorder (PTSD). [38]

According to van der Kolk, memories of highly significant events are usually accurate and stable over time; aspects of traumatic experiences appear to get stuck in the mind, unaltered by time passing or experiences that may follow. The imprints of traumatic experiences appear to be different from those of nontraumatic events, perhaps because of alterations in attentional focusing or the fact that extreme emotional arousal interferes with memory .[21] van der Kolk and Fisler’s hypothesis is that under extreme stress, the memory categorization system based in the hippocampus fails, but these memories to be kept as emotional and sensory states. When these traces are remembered and put into a personal narrative, they are subject to being condensed, contaminated and embellished upon.

When there is inadequate recovery time between stressful situations, alterations may occur to the stress-response system, some of which may be irreversible, and cause pathological responses, which may memory loss, learning deficits and other maladaptive symptoms. In animal studies, high levels of cortisol can cause hippocampal damage, which may cause short-term memory deficits; in humans, MRI studies have shown reduced hippocampal volumes in combat veterans with PTSD, adults with posttraumatic symptoms and survivors of repeated childhood sexual or physical abuse. Trauma may also interfere with implicit memory, where periods of avoidance may be interrupted by intrusive emotional occurrences with no story to guide them.[39] A difficult issue is whether those presumably abused accurately recall their experiences. [40]

Professional Organisations

The Working Group on Investigation of Memories of Child Abuse of the American Psychological Association presented findings mirroring those of the other professional organizations (see External Links subpage for references to various statements made independently by these organisations). The Working Group made five key conclusions:

(1) Controversies regarding adult recollections should not be allowed to obscure the fact that child sexual abuse is a complex and pervasive problem in America that has historically gone unacknowledged;

(2) Most people who were sexually abused as children remember all or part of what happened to them;

(3) It is possible for memories of abuse that have been forgotten for a long time to be remembered;

(4) It is also possible to construct convincing pseudo-memories for events that never occurred; and

(5) There are gaps in our knowledge about the processes that lead to accurate and inaccurate recollections of childhood abuse. [41]

References

  1. Geraerts E et al. (2009) Cognitive mechanisms underlying recovered-memory experiences of childhood sexual abuse. Psychol Sci 20:92-8. PMID 19037903
  2. Brewin CR, Andrews B (1998) Recovered memories of trauma: phenomenology and cognitive mechanisms. Clin Psychol Rev 18:949-70. PMID 9885769 ( The data ...strongly support the likelihood that some recovered memories correspond to actual experiences.)
  3. Loftus EF, Davis D (2006) Recovered memories. Annu Rev Clin Psychol 2:469-98. PMID 17716079
  4. Paul Fink et al. (19 August 2005), "Letters to the editor: The Problem of Child Sexual Abuse", Science 309 (5738): 1182-84, DOI:10.1126/science.309.5738.1182b
  5. See Policy Forum in Science (2005) and ensuing correspondence. Freyd JJ et al. (2005) Psychology. The science of child sexual abuse. Science (Policy Forum) 308:501. PMID 15845837 Quote from Kihlstrom JF et al. in response in Science 309:1182-5 PMID 16114120 with authors' reply
  6. Gonsalves B, Paller KA (2002) Mistaken memories: remembering events that never happened. Neuroscientist 8:391-5. PMID 12374423
  7. Williams LM (1994). "Recall of childhood trauma: a prospective study of women's memories of child sexual abuse". J Consult Clin Psychol 62: 1167–76. PMID 7860814[e]
  8. Laney C, Loftus EF (2005) Traumatic memories are not necessarily accurate memories. Can J Psychiatry 50:823-8. PMID 16483115
  9. See Loftus E (1997) Creating false memories Scientific American 227 no 3 for a popular account
  10. Porter S et al.(1999) The nature of real, implanted, and fabricated memories for emotional childhood events: implications for the recovered memory debate. Law Hum Behav 23:517-37 PMID 10487147
  11. 11.0 11.1 Crook, L (1999). "Lost in a shopping mall--A breach of professional ethics.". Ethics Behavior. 9: 39–50. DOI:10.1207/s15327019eb0901_3. Research Blogging.
  12. Pope, K (1996). "Memory, abuse, and science: questioning claims about the false memory syndrome epidemic". Am Psychologist 51: 957. DOI:10.1037/0003-066X.51.9.957. Research Blogging.
  13. Brandon S et al. (1998) Recovered memories of childhood sexual abuse. Implications for clinical practice. Br J Psychiatry 172:296-307. PMID 9722329
  14. Questions and Answers about Memories of Childhood Abuse American Psychiatric Association
  15. Sheflin and Brown state that a total of 25 studies on amnesia for child sexual abuse exist and that they demonstrate amnesia in their study subpopulations. Sheflin, AW; Brown D (1996). "Repressed memory or dissociative amnesia: what the science says". J Psychiat Law 24: 143–88. ISSN = 0093-1853 =. . An editorial in the British Medical Journal however, prefaces mention of the Sheflin and Brown study with "on critical examination, the scientific evidence for repression crumbles.""Harrison G Pope", British Medical Journal (BMJ) 316 (7130), 14 February 1998
  16. 16.0 16.1 Hammond, D. Corydon; Brown, Daniel P.; Scheflin, Alan W. (1998). Memory, trauma treatment, and the law. New York: W.W. Norton. ISBN 0-393-70254-5. 
  17. Chu, JA; et al. (1999). "Memories of childhood abuse: Dissociation, amnesia and corroboration.". Am J Psychiatry 156: 749-55. “Childhood abuse, particularly chronic abuse beginning at early ages, is related to the development of high levels of dissociative symptoms including amnesia for abuse memories. This study suggests that psychotherapy usually is not associated with memory recovery and that independent corroboration of recovered memories of abuse is often present.”
  18. Whitfield M.D., Charles L.. Memory and Abuse - Remembering and Healing the Effects of Trauma. Health Communications, Inc. ISBN 1-55874-320-0. “16% to 64% were found to have delayed memories (traumatic forgetting) of having been sexually abused or traumatized in other ways” 
  19. 19.0 19.1 Dalenberg C (2006) Recovered memory and the Daubert criteria: recovered memory as professionally tested, peer reviewed, and accepted in the relevant scientific community. Trauma Violence Abuse 7:274-310. PMID 17065548 ("Research during the past two decades has firmly established the reliability of the phenomenon of recovered memory")
  20. Kluft, RP (1995). "The confirmation and disconfirmation of memories of abuse in Dissociative Identity Disorder patients: A naturalistic study". Dissociation 8: 253-8. “The charts of 34 dissociative identity disorder (DID) patients in treatment with the author were reviewed for instances of the confirmation or disconfirmation of recalled episodes of abuse occurring naturalistically in the course of their psychotherapies. Nineteen, or 56%, had instances of the confirmation of recalled abuses. Ten of the 19, or 53%, had always recalled the abuses that were confirmed. However, 13 of the 19, or 68%, obtained documentation of events that were recovered in the course of therapy, usually with the use of hypnosis. Three patients, or 9%, had instances in which the inaccuracy of their recollection could be demonstrated.”
  21. 21.0 21.1 21.2 van der Kolk, BA & R Fisler (1995), "Dissociation and the fragmentary nature of traumatic memories: Overview and exploratory study", J Traumatic Stress 8: 505–25 "a systematic exploratory study of 46 subjects with PTSD which indicates that traumatic memories are retrieved, at least initially, in the form of dissociated mental imprints of sensory and affective elements of the traumatic experience: as visual, olfactory, affective, auditory and kinesthetic experiences. Over time, subjects reported the gradual emergence of a personal narrative that some believe can be properly referred to as "explicit memory"....Of the 35 subjects with childhood trauma, 15 (43%) had suffered significant, or total amnesia for their trauma at some time of their lives. Twenty seven of the 35 subjects with childhood trauma (77%) reported confirmation of their childhood trauma." Cite error: Invalid <ref> tag; name "Van1995" defined multiple times with different content
  22. An article by Cheit, RE (1998). "Consider this, skeptics of recovered memory". Ethics Behav 8: 141–60. DOI:10.1207/s15327019eb0802_4. Research Blogging.
  23. Herman, J. L. (1997). Trauma and recovery. New York: Basic Books, 290. ISBN 0-465-08730-2. “The ordinary response to atrocities is to banish them from consciousness.” 
  24. Herman, J L.; Schatzow E (1987). "Recovery and verification of memories of childhood sexual trauma.". Psychoanalytic Psychol 4. “Three out of four patients were able to validate their memories by obtaining corroborating evidence from other sources”
  25. Stocks JT (1998) Recovered memory therapy: a dubious practice technique. Soc Work 43:423-36 PMID 9739631
  26. Kihlstrom JF (1997) Hypnosis, memory and amnesia. Philos Trans R Soc Lond B Biol Sci 29:3521727-32. PMID 9415925 ("Hypnotized subjects respond to suggestions from the hypnotist for imaginative experiences involving alterations in perception and memory. ... Hypnotic hypermnesia refers to improved memory for past events. However, such improvements are illusory: hypermnesia suggestions increase false recollection, as well as subjects' confidence in both true and false memories. Hypnotic age regression can be subjectively compelling, but does not involve the ablation of adult memory, or the reinstatement of childlike modes of mental functioning, or the revivification of memory. The clinical and forensic use of hypermnesia and age regression to enhance memory in patients, victims and witnesses (e.g. recovered memory therapy for child sexual abuse (CSA)) should be discouraged.")
  27. 'Scientific Status of Refreshing Recollection by the Use of Hypnosis' (1985) JAMA 253: 1918-23. PMID 3974082
  28. Boakes J (1999) False complaints of sexual assault: recovered memories of childhood sexual abuse. Med Sci Law 39:112-20. PMID 10332158 '
  29. DSM-IV Diagnostic and Statistical Manual, American Psychiatric Association
  30. Whitfield, Charles L.; Joyanna L. Silberg, Paul Jay Fink (2001). Misinformation Concerning Child Sexual Abuse and Adult Survivors. Haworth Press, 56. ISBN 0789019019. 
  31. Scheflin, A (1999), "Ground Lost: the False Memory/Recovered Memory Therapy Debate", Psychiatric Times 16
  32. “The Validity of Recovered Memory: Decision of a US District Court” Judge Edward F. Harrington, Presentation by Jim Hopper, Ph.D. The legal documentation citation is: 923 Federal Supplement 286 (D. Mass. 1996), United States District Court - District of Massachusetts Ann Shahzade, plaintiff Civil Action No.: V. 92-12139-EFH George Gregory, Defendant. [1]
  33. Porter S et al. (2001), "Memory for murder. A psychological perspective on dissociative amnesia in legal contexts", Int J Law Psychiatry 24: 23-42
  34. Zola SM (1998) Memory, amnesia, and the issue of recovered memory: neurobiological aspects. Clin Psychol Rev 18:915-32. PMID 9885767
  35. Diagnostic and Statistical Manual of Mental Disorders
  36. Freyd, J (1994). "Betrayal trauma: Traumatic amnesia as an adaptive response to childhood abuse". Ethics Behav 4: 307–29.
  37. van der Kolk, Bessel (1994), "The body keeps the score: memory and the evolving psychobiology of posttraumatic stress", Harvard Rev Psychiat 1: 253–65, DOI:10.3109/10673229409017088
  38. Diagnostic symptoms of PTSD include reexperience such as flashbacks and nightmares, difficulty falling or staying asleep, feelings of panic or fear, depression, headache, and physiological symptoms including irregular heartbeat and diarrhoea.Post Traumatic Stress Disorder (PTSD) The Royal College of Psychiatrists
  39. Cite error: Invalid <ref> tag; no text was provided for refs named Knopp1996
  40. Bremner, JD (2002). Does Stress Damage the Brain? Understanding Trauma-Related Disorders from a Neurological Perspective. New York: W.W. Norton and Company. 
  41. Colangelo JJ (2007) Recovered memory debate revisited: practice implications for mental health counselors.(PRACTICE)Journal of Mental Health Counseling