Recovered memory corroboration rates

There are many studies that show fairly high corroboration rates for recovered memories.

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.”

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.

“Recovered memories of abuse among therapy patients: A national survey.” Pope, Kenneth S.; Tabachnick, Barbara G.  Independent practice, Norwalk, CT, US Ethics & Behavior 1995 Vol 5(3) 237-248, “According to the therapists, about 50% of the patients who claimed to have recovered the memories had found external validation, a percentage that coincides with that obtained in the Feldman-Summers & Pope, 1994 study”

Corroboration of Child Abuse Memories “Studies vary in frequency. Between 31 and 64 percent of abuse survivors in six major studies reported that they forgot “some of the abuse.” Numbers reporting severe amnesia ranged from under 12% to 59%….Studies report 50-75% of abuse survivors corroborating the facts of their abuse through an outside source. Reference: Bowman, Elizabeth. Delayed Memories of Child Abuse: Part I: An Overview of Research Findings on Forgetting, Remembering, and Corroborating Trauma. Dissociation, IX (4) pp. 221-231

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.”

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.
One hundred twenty-nine women with previously documented histories of sexual victimization in childhood were interviewed and asked detailed questions about their abuse histories to answer the question “Do people actually forget traumatic events such as child sexual abuse, and if so, how common is such forgetting?” A large proportion of the women (38%) did not recall the abuse that had been reported 17 years earlier. Women who were younger at the time of the abuse and those who were molested by someone they knew were more likely to have no recall of the abuse. The implications for research and practice are discussed. Long periods with no memory of abuse should not be regarded as evidence that the abuse did not occur.

How often do children’s reports of abuse turn out to be false? Research has consistently shown that false allegations of child sexual abuse by children are rare. Jones and McGraw examined 576 consecutive referrals of child sexual abuse to the Denver Department of Social Services, and categorized the reports as either reliable or fictitious. In only 1% of the total cases were children judged to have advanced a fictitious allegation. Jones, D. P. H., and J. M. McGraw: Reliable and Fictitious Accounts of Sexual Abuse to Children.Journal of Interpersonal Violence, 2, 27-45, 1987. In a more recent study, investigators reviewed case notes of all child sexual abuse reports to the Denver Department of Social Services over 12 months. Of the 551 cases reviewed, there were only 14 (2.5%) instances of erroneous concerns about abuse emanating from children. These consisted of three cases of allegations made in collusion with a parent, three cases where an innocent event was misinterpreted as sexual abuse and eight cases (1.5%) of false allegations of sexual abuse. Oates, R. K., D.P. Jones, D. Denson, A. Sirotnak, N. Gary, and R.D. Krugman: Erroneous Concerns about Child Sexual Abuse. Child Abuse & Neglect 24:149-57, 2000….Children Tend to Understate Rather than Overstate the Extent of Any Abuse Experienced – Research with children whose sexual abuse has been proven has shown that children tend to minimize and deny abuse, not exaggerate or over-report such incidents.

Duggal, S., & Sroufe, L. A. (1998). Recovered memory of childhood sexual trauma: A documented case from a longitudinal study. Journal of Traumatic Stress, 11(2), 301-321. A case of recovered memory of childhood trauma is reported with documented sexual trauma in early childhood, chronicled evidence of the absence of memory for traumatic experience over a period of time, and substantial evidence of spontaneous recovery of memory.

“Child Maltreatment, Vol. 2, No. 2, 91-112 (1997) DOI: 10.1177/1077559597002002001 Videotaped Discovery of a Reportedly Unrecallable Memory of Child Sexual Abuse: Comparison with a Childhood Interview Videotaped 11 Years Before David L. Corwin, Erna Olafson….This article presents the history, verbatim transcripts, and behavioral observations of a child’s disclosure of sexual abuse to Dr. David Corwin in 1984 and the spontaneous return of that reportedly unrecallable memory during an interview between the same individual, now a young adult, and Dr. Corwin 11 years later. Both interviews were videotape recorded.”

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”

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.”
full article:

From Research discussing corroboration and accuracy of recovered memories An Annotated Bibliography by Lynn Crook
(see this bibliography for more detailed information)

Andrews, B., Brewin, C., Ochera, J., Morton, J., Bekerian, D., Davies, G., and Mollon, P. (1999). Characteristics, context and consequences of memory recovery among adults in therapy. Brit J Psychiatry 175:141-146.
Abstract: One-hundred and eight therapists provided information on all clients with recovered memories seen in the past three years, and were interviewed in detail on up to three such clients. Of a total of 690 clients, therapists reported that 65% recalled child sexual abuse and 35% recalled other traumas, 32% started recovering memories before entering therapy. According to therapists’ accounts, among the 236 detailed client cases, very few appeared improbable and corroboration was reported in 41%. Most (78%) of the clients’ initial recovered memories either preceded therapy or preceded the use of memory recovery techniques used by the respondents. Techniques seemed to be used more to help the clients to elaborate the memories than to facilitate their initial recovery. Clients with whom techniques had been used before the first reported memory recovery were no less likely to have found corroborating evidence than clients with whom no techniques had been used before memory recovery. Some of the data are consistent with memories being of iatrogenic origin, but other data clearly point to the need for additional explanations.

Bagley, C. (1995). The prevalence and mental health sequels of child sexual abuse in community sample of women aged 18 to 27. Child sexual abuse and mental health in adolescents and adults. Aldershot: Avebury.
Abstract: Study of women 18-24 years who had been removed from home 10 years previously by social services due to intrafamilial sexual abuse. Of the 19 women for whom there was evidence of serious sexual abuse, 14 remembered events corresponding to their records. Two remembered that abuse had taken place but could recall no specific details, and three had no memory. Two of the last three described long blank periods for the memory of childhood corresponding to the age when abuse had taken place.

Bull, D. (1999). A verified case of recovered memories of sexual abuse. American Journal of Psychotherapy, 53(2), 221-224.
Abstract: A case is presented that shows verifiable evidence of repression at work. Rachel, a 40-year-old woman with no history of mental illness and ten years of exemplary professional work, recovers memories of childhood sexual abuse by her father through a call from her youth pastor in whom she had confided as an adolescent.

Dahlenberg, C. (1996, Summer) Accuracy, timing and circumstances of disclosure in therapy of recovered and continuous memories of abuse. The Journal of Psychiatry and Law.
Abstract: Seventeen patients who had recovered memories of abuse in therapy participated in a search for evidence confirming or refuting these memories. Memories of abuse were found to be equally accurate whether recovered or continuously remembered. Predictors of number of memory units for which evidence was uncovered included several measures of memory and perceptual accuracy. Recovered memories that were later supported arose in psychotherapy more typically during periods of positive rather than negative feelings toward the therapist, and they were more likely to be held with confidence by the abuse victim.

Feldman-Summers, S., & Pope, K. S. (1994). The experience of forgetting childhood abuse: A national survey of psychologists. Journal of Consulting and Clinical Psychology, 62, 636-639.
Abstract: A national sample of psychologists were asked whether they had been abused as children and, if so, whether they had ever forgotten some or all of the abuse. Almost a quarter of the sample (23.9%) reported childhood abuse, and of those, approximately 40% reported a period of forgetting some or all of the abuse. The major findings were that (a) both sexual and nonsexual abuse were subject to periods of forgetting; (b) the most frequently reported factor related to recall was being in therapy; (c) approximately one half of those who reported forgetting also reported corroboration of the abuse; and (d) reported forgetting was not related to gender or age of the respondent but was related to severity of the abuse.
Summary: 330 psychologists. 24% physical and 22% sexual abuse. Of those abused, 40% did not remember at some time. 47% had corroboration. 56% said psychotherapy aided in recall. Differences between those who first recalled abuse in therapy and those who recalled it elsewhere were not significant.

Herman, J. L., & Harvey, M. R. (1997). Adult memories of childhood trauma: A naturalistic clinical study. Journal of Traumatic Stress, 10, 557-571.
The clinical evaluations of 77 adult outpatients reporting memories of childhood trauma were reviewed. A majority of patients reported some degree of continuous recall. Roughly half (53%) said they had never forgotten the traumatic events. Two smaller groups described a mixture of continuous and delayed recall (17%) or a period of complete amnesia followed by delayed recall (16%). Patients with and without delayed recall did not differ significantly in the proportions reporting corroboration of their memories from other sources. Idiosyncratic, trauma-specific reminders and recent life crises were most commonly cited as precipitants to delayed recall. A previous psychotherapy was cited as a factor in a minority (28%) of cases. By contrast, intrusion of memories after a period of amnesia was frequently cited as a factor leading to the decision to seek psychotherapy. The implications of these findings are discussed with respect to the role of psychotherapy in the process of recovering traumatic memories.

Lewis, D., Yeager, C., Swica, Y., Pincus, J. and Lewis, M. (1997). Objective documentation of child abuse and dissociation in 12 murderers with dissociative identity disorder. Am J Psychiatry, 154(12):1703-10.
OBJECTIVE: The skepticism regarding the existence of dissociative identity disorder as well as the abuse that engenders it persists for lack of objective documentation. This is doubly so for the disorder in murderers because of issues of suspected malingering. This article presents objective verification of both dissociative symptoms and severe abuse during childhood in a series of adult murderers with dissociative identity disorder. METHOD: This study consisted of a review of the clinical records of 11 men and one woman with DSM-IV-defined dissociative identity disorder who had committed murder. Data were gathered from medical, psychiatric, social service, school, military, and prison records and from records of interviews with subjects’ family members and others. Handwriting samples were also examined. Data were analyzed qualitatively. RESULTS: Signs and symptoms of dissociative identity disorder in childhood and adulthood were corroborated independently and from several sources in all 12 cases; objective evidence of severe abuse was obtained in 11 cases. The subjects had amnesia for most of the abuse and underreported it. Marked changes in writing style and/or signatures were documented in 10 cases. CONCLUSIONS: This study establishes, once and for all, the linkage between early severe abuse and dissociative identity disorder. Further, the data demonstrate that the disorder can be distinguished from malingering and from other disorders. The study shows that it is possible, with great effort, to obtain objective evidence of both the symptoms of dissociative identity disorder and the abuse that engenders it.

Martinez-Taboas, A. (1996). Repressed memories: Some clinical data contributing toward its elucidation. American Journal of Psychotherapy, 50(2), 217-30.
Abstract: Recently there has been considerable controversy about the validity of memories recovered during psychotherapy. In the last two decades, a plethora of studies have been published that leave no reasonable doubt that many children are victimized and abused. Proponents of false memory syndrome have taken the position that “memories” that surface in the course of psychotherapy are not the product of real traumas, but are instead,”pseudomemories” implanted by therapists through techniques such as hypnosis and abreactions. In response to these claims, the author presents two well documented and corroborated cases of dissociated or delayed memories of child sexual abuse in patients with a diagnosis of Dissociative Identity Disorder (DID). The patients had absolutely no conscious memory of their childhood abusive experiences and in both cases the author obtained definite and clear cut independent corroboration of the realities of the abuse. The amnesia was documented and memories were recovered in the course of treatment. Only through the publication of clear cut cases can the debate about repressed memories be settled in an empirical way.

Viederman M. (1995). The reconstruction of a repressed sexual molestation fifty years later. Journal of the American Psychoanalytic Association, 43(4): 1169-1219.
Summary: Reconstruction of a previously completely repressed memory of sexual molestation. Six years following termination of analysis, the patient wrote a letter describing a confirmation of the event, now sixty years past, from the sole other survivor of the period who had knowledge of what had happened.

Westerhof, Y., Woertman, L. Van der Hart, O., & Nijenhuis, E.R.S. (2000). Forgetting child abuse: Feldman-Summers and Pope’s (1994) study replicated among Dutch psychologists. Clinical Psychology and Psychotherapy, 7, 220-229.
Abstract: In a replication of Feldman-Summers and Pope’s (1994) national survey of American psychologists on ‘forgetting’ childhood abuse, a Dutch sample of 500 members of the Netherlands Institute of Psychologists (NIP) were asked if they had been abused as children and, if so, whether they had ever forgotten some or all of the abuse for soem significant period of time. As compared to the 23.9% in the original study, 13.3% reported childhood abuse. Of that subgroup, 39% (as compared to 40% in the original study) reported a period of forgetting some or all of the abuse for a period of time. Both sexual and non-sexual physical abuse were subject to forgetting, which in 70% of cases was reversed while being in therapy. Almost 70% of those who reported forgetting also reported corroboration of the abuse. The forgetting was not related to gender or age, but was associated with the reported early abuse onset. These results were remarkably similar to the results of the Feldman-Summers and Pope’s original study.

Widom, C. and Shepard, R. (1996). Accuracy of adult recollections of childhood victimization: Part 1. Psychological Assessment, 8(4), 412-421.
Abstract: Using data from a study with prospective-cohorts design in which children who were physically abused, sexually abused, or neglected about 20 years ago were followed up along with a matched control group, accuracy of adult recollections of childhood physical abuse was assessed. Two hour in-person interviews were conducted in young adulthood with 1,196 of the original 1,575 participants. Two measures (including the Conflict Tactics Scale) were used to assess histories of childhood physical abuse. Results indicate good discriminant validity and predictive efficiency of the self-report measures, despite substantial underreporting by physically abused respondents. Tests of construct validity reveal shared method variance, with self-report measures predicting self-reported violence and official reports of physical abuse predicting arrests for violence. Findings are discussed in the context of other research on the accuracy of adult recollections of childhood experiences.

Widom, C. and Shepard, R. (1997). Accuracy of adult recollections of childhood victimization. Part 2. Childhood sexual abuse. Psychological Assessment 9: 34-46.
Summary: A prospective study in which abused and neglected children (court substantiated) [N=1,114] were matched with non-abused and neglected children and followed into adulthood. There was substantial underreporting of sexual abuse, when compared to court and medical records. Victimization recall was checked by comparing crimes disclosed in victimization surveys found in police records. The question should be not whether reports of childhood sexual abuse are valid or not, but what is the best way to ask questions to make answers more valid.

Williams, L. M. (1995, October). Recovered memories of abuse in women with documented child sexual victimization histories. Journal of Traumatic Stress, 8(4).
Abstract: This study provides evidence that some adults who claim to have recovered memories of sexual abuse recall actual events that occurred in childhood. One hundred twenty-nine women with documented histories of sexual victimization in childhood were interviewed and asked about abuse history. Seventeen years following the initial report of the abuse, 80 of the women recalled the victimization. One in 10 women (16% of those who recalled the abuse) reported that at some time in the past they had forgotten about the abuse. Those with a prior period of forgetting – the women with “recovered memories” – were younger at the time of abuse and were less likely to have received support from their mothers than the women who reported that they had always remembered their victimization. The women who had recovered memories and those who had always remembered had the same number of discrepancies when their accounts of the abuse were compared to the reports from the early 1970’s.

Brown, D., Scheflin, A., and Whitfield, C. (1999). Recovered memories: the current weight of the evidence in science and in the courts. The Journal of Psychiatry & Law 27/Spring 1999

From  How People Forget: The Truth About Delayed Memory Studies of Delayed Memory

That dissociation and amnesia are relatively common in child sexual abuse survivors is well-documented. There have been several recent studies that verify the repression of trauma and the fact of delayed memories: In a survey of 450 adults in treatment for child sexual abuse, 59% had periods in which they could not remember the abuse. (Briere and Conte, in press). Briere, John. “Studying Delayed Memories of Childhood Sexual Abuse.” The APSAC Advisor, Summer 1992.

In a study of 53 women in therapy, Judith Herman and Emily Schatzow found that 74% were able to obtain corroborating evidence for the abuse, through witnesses, offenders’ diaries, pornographic pictures, offender confessions, and other sources. Nine percent found evidence that was “strongly suggestive, but not conclusive;” 11% did not try to confirm their memories; and only 6% found no supportive evidence. The conclusion of the researchers was that, “delayed recall of sexual abuse is as verifiable as any other form of disclosure.” Herman, Judith L. And Mary R. Harvey. “The False Memory Debate: Social Science or Social Backlash?” The Harvard Mental Health Letter, Volume 9, Number 10, April 1993.

Interviews were conducted with 100 women who as children reported sexual abuse in 1973, 1974 or 1975. The records of these girls were obtained from a city hospital emergency department which had interviewed the girls and the families and collected forensic evidence. In 1990 and 1991 the women, aged 18-31, were interviewed for two hours for what they were told was a study that examined the lives and health of women who obtained care at the hospital. In the course of the interview, the women were asked about their childhood experiences with sex. They were asked whether they or their families had ever reported childhood sexual abuse, or if anyone in their family ‘got in trouble’ for his or her sexual activities. Thirty-eight percent of the women either did not remember the abuse or chose not to report it to the interviewer. The interviewer states,”…qualitative analysis of these reports and non-reports suggests that the vast majority of the 38% were women who did not remember the abuse. They responded openly to other personal matters, and over one-half of the women who were amnestic reported other childhood victimizations.” Williams, Linda M. “Adult Memories of Childhood Abuse: Preliminary Findings from a Longitudinal Study.” The APSAC Advisor, Summer 1992.

Recovered Memories of Sexual Abuse  Scientific Research & Scholarly Resources
At least 10% of people sexually abused in childhood will have periods of complete amnesia for their abuse, followed by experiences of delayed recall

101 corroborated cases of recovered memory

Summary of Research Examining the Prevalence of Full or Partial  Dissociative Amnesia for Traumatic Events
The most comprehensive review of the scientific literature on dissociative amnesia has been conducted by Brown, Scheflin and Hammond in their book, Memory, Trauma Treatment, and the Law . (New York: Norton, 1998). This book is viewed as setting the standard in the field after receiving the American Psychiatric Association’s 1999 prestigious Manfred S. Guttmacher Award for best book in law and forensic psychiatry.
Brown, Scheflin and Hammond reviewed 43 studies relevant to the subject of traumatic memory and found that every study that examined the question of dissociative amnesia in traumatized populations demonstrated that a substantial minority partially or completely forget the traumatic event experienced, and later recover memories of the event.
By 1999, over 68 studies had been published that document dissociative amnesia after childhood sexual abuse. In fact, no study that has looked for evidence of traumatic or dissociative amnesia after child sexual abuse has failed to find it. see: Brown, Scheflin, & Whitfield. (1999). Recovered Memories: The Current Weight of the Evidence in Science and in the Courts, Journal of Psychiatry & Law, 27, 5-156.

What about Recovered Memories? Jennifer J. Freyd, University of Oregon

Memory disturbances and dissociative amnesia in Holocaust survivors