This paper will delineate the etiological antecedents of Dissociative Identity Disorder (DID) and enumerate upon the scientific evidence proving the existence of DID. (I will use the term DID for MPD to avoid confusion, even when the original author cited may have used the original term MPD.) This paper will explain the diagnostic criteria of DID, its incidence rates and cross-cultural characteristics, present arguments to counter the idea that suggestibility may be a factor in its misdiagnosis and delineate the data that shows a clear connection between traumatic wartime experiences and dissociation and trauma and DID. It will also consider the historical development of the debate surrounding DID, including its increased diagnosis around the turn of the last century, reasons for its decline in diagnosis in the mid part of the last century and reasons for its increased diagnosis toward the end of the 20th century. It will deliberate upon the claims made by several researchers that DID can be created in the laboratory as well as the critiques surrounding those claims. I will also discuss the neurobiological evidence proving the connection between DID and certain neurobiological indicators. Included will be a discussion of the modern theory of iatrogenic DID and a critique of this theory. A debate about the creation of DID as a social construction and critiques of this theory are presented as well. To conclude, I will present the argument that the research on DID showing it to be a valid psychiatric diagnosis which robustly meets all the necessary validity requirements.

DID is defined in the DSM-IV-TR as the presence of two or more personality states or distinct identities that repeatedly take control of one’s behavior. The patient has an inability to recall personal information. The extent of this lack of recall is too great to be explained by normal forgetfulness. The disorder cannot be due to the direct physical effects of a general medical condition or substance. (American Psychological Association, 2000).

DID entails a failure to integrate certain aspects of memory, consciousness and identity. Patients experience frequent gaps in their memory for their personal history, past and present. Patients with DID report having severe physical and sexual abuse, especially during childhood. There is controversy around these reports, because childhood memories may be exposed to distortion and some patients with DID are highly hypnotizable and vulnerable to suggestive influences. But, the reports of patients with DID are often validated by objective evidence. People that are responsible for acts of sexual and physical abuse may be prone to distorting or denying their behavior. (American Psychological Association, 2000)

Physical evidence may include variations in physiological functions in different identity states, including differences in vision, levels of pain tolerance, symptoms of asthma, the response of blood glucose to insulin and sensitivity to allergens. Other physical findings may include scars from physical abuse or self-inflicted injuries, headaches or migraines, asthma and irritable bowel syndrome. (American Psychological Association, 2000)

DID is found in a variety of cultures around the world. It is diagnosed three to nine times more often in adult females than males. Females average 15 or more identities, males eight identities. The sharp rise in the reported cases of DID in the U.S. may be due the greater awareness of DID’s diagnosis, which has caused an increased identification of those that were previously undiagnosed. Others believe it has been overdiagnosed in those that are highly suggestible. (American Psychological Association, 2000)

Pezdek and Roe investigated some misinformation suggestibility studies and found that the misinformation suggestibility effect may not be easily generalizable to false memories caused by therapeutic suggestions. Pezdek and Grand in separate papers state that there are no independent cases of false memory. Pezdek and Roe found that strong memories are more resistant to suggestion than weak memories. They also found that it is fairly easy to suggestively influence someone to believe that a different event occurred other than the event experienced. But, a large number of experimental subjects rejected a suggested planted memory for an event that had never occurred at all. Pezdek, Finger and Hodge tested the hypothesis that an event must be evaluated as true before it can be put into autobiographical memory. They found that familiar false events were much most likely to be put into autobiographical memory than unfamiliar false events. They even tested suggesting two false events to 20 subjects, one was being lost in a mall, the other was being given a rectal enema. Three accepted the familiar false suggestion of being lost in a mall, but none accepted the unfamiliar suggestion of being given an enema. (Brown, Frischholz & Scheflin, 1999) These studies would back up the idea that it is difficult if not impossible to suggest to a patient that they have DID.

The average time period from DID’s first presentation of symptoms to its diagnosis is six to seven years. DID may become less manifest as patients reach past their late 40’s, but it can reemerge during stress, trauma or substance abuse. It is suggested in several studies that DID is more likely to occur with first-degree biological relatives of people that already have DID, than in the regular population. (American Psychological Association, 2000)

Research by Putnam has shown that the vast majority of dissociative disorders were induced traumatically. Wartime amnesic syndromes give us excellent documentation showing the connections between dissociative reactions and trauma. A substantial percentage of those that have fought in wars have either complete or partial amnesia for their combat experiences. Part of war-induced posttraumatic stress reactions include persistent feelings of estrangement and detachment, and active dissociative phenomena like abreactions and flashbacks. Estimates of the rates of dissociative syndromes during wartime, usually psychogenic fugue reactions or psychogenic amnesia run in a variety of studies done in the World War II era between five and 14%. One study by Kirshner in the early 1970’s showed the overall dissociative reaction’s rate among peacetime military psychiatric patients at 1.3%. In Abeles and Schilder’s 1935 study of psychogenic amnesia patients at Bellevue Hospital, they observed that an unpleasant conflict, familial or financial was significant as the amnesia’s immediate cause. A variety of studies have shown a high incidence of depersonalization syndromes in those that have survived experiences that were life-threatening, like being in a concentration camp. There is strong evidence linking the genesis of DID to recurrent, severe traumatic experiences that usually happen in childhood or early adolescence. Trauma in childhood has also been identified as contributing to the beginning of hypnoid states. (Putnam, 1989)

The original explanations of multiple personality as being derived from a supernatural etiology like reincarnation or spirit possession during the 19th century have pretty much disappeared. From about 1880 to 1920 physiological explanations of DID often described some sort of hemispheric disconnection syndrome came about due to the discovery of lateralization of some brain functions like speech. From 1920 to 1970, there was a considerable decline in the number of reported cases of DID. Iatrogenic creation by hypnosis and role playing were often commonly offered as explanations. These theories occur today in modified forms. State dependent learning was also proposed as an explanation for DID in the early 1900’s. (Putnam, 1989)

Historically by 1910, a believable view of DID began to decline, partly due to the increase in psychoanalysis and then behaviorism, and partly due to skeptical views toward hypnosis and the connection between hypnosis and hysteria. During the period of decline, Taylor and Martin reviewed 76 cases in the literature from the 1800’s to the mid 1940’s. They found that even though some multiple personalities may have been caused by suggestion, they concluded that multiple personality is a genuine phenomenon. This is because of the wide spread of these cases, because most of them had no information about other cases and because they had been judged as authentic sufferers of multiplicity by different observers. Sutcliffe and Jones believed the number of cases reported in the late 1800’s was increased by misdiagnosis. They added that many of the cases of DID could not be simply dismissed as simply being incorrectly diagnosed. They also stated that though shaping has played a part in the development of multiple personality cases, it doesn’t explain the nonexistence of these cases. Some cases manifested multiple behavior prior to therapy. They concluded that one should reject the idea that shaping in hypnosis may explain DID, but multiple behaviors can be shaped in those that already have DID. (Brown et al., 1999)

Estabrooks worked with the experimental creation of personality states in the 1920’s. He was trying to create hypnotically programmed couriers for certain intelligence agencies. The extent of his success of creating artificial DID for the military is unclear, since publication was not encouraged. The CIA however, formally conducted such experiments with Estabrooks consultation for some in the 1950’s. He claims to have created unconscious couriers that were amnesic for specific information. None of his work describes a single case in any detail, nor do any of his writings show that he succeeded in creating DID. (Brown et al., 1999)

Harriman extended Estabrooks work by inducing a profound hypnotic trance in good hypnotic subjects and then he suggested a role to produce automatic writing in a subject. The subject’s arm and hand had been dissociated from the body by hypnotic suggestion. He claims the subjects were like different persons when they did the writing. Problems with Harriman’s work include his repeated work with a small number of subjects, that he did not control for extraneous variables and that the secondary personality states he created were, for the most part, temporary states produced partially by the subject, which were used to explain dissociated experiences. He experimentally failed to meet the criteria of the DSM-IV-TR, where an alter personality must take executive control. His personalities produced ineffectual, poorly acted and complaint personalities limited to the demonstrations he made. (Brown et al., 1999)

By the mid 1960’s, government researchers for the defense department and the CIA were aware of the information on how to heal victims of severe early trauma, so they were able to reverse the process. Their goal was to take a child under age seven, create a unique personality and train it to be a killer so that no other ego states would be aware of this training or any acts this personality would commit. Each personality was created by trauma, usually sexual in nature. (Hersha, Hersha, Griffis & Schwartz, 2001)

Misdiagnosis of patients with DID may have also caused some confusion in the earlier development of the explanations of the etiology of DID. Rosenbaum notes that the diagnosis of schizophrenia became popular in the late 1920’s. Starting in about 1927, there was a sharp decline in the number of diagnoses of DID matched by a sharp increase in the diagnosis of schizophrenia. Bleuer (who originally introduced the diagnosis of schizophrenia in 1908) included multiple personality in his description of schizophrenia. It is probable that patients with DID were misdiagnosed as suffering from schizophrenia during this time. A variety of studies during the 1980’s (Putnam, Bliss, Bliss and Jeppsen) have shown that DID patients were often misdiagnosed as having schizophrenia. A decrease in patient/clinician interaction due to the psychopharmalogical development of neuroleptics, like Thorazine, may also have added to the decreased recognition of the sufferers of DID, who often need a long period of close therapy before being able to reveal their dissociative experiences and amnesias. (Putnam, 1989)

The connection between DID and childhood trauma has slowly come out in the last century. The slow recognition of the connection between the two was due to the fact that few clinicians worked with more than one case and it was also due to the fact that there wasn’t enough stringent diagnostic criteria, which caused an overlap with other disorders, such as organic amnesias, epilepsy and psychogenic fugue. In the 1970’s, early reports that clearly connected DID to childhood trauma appeared in single case histories, like Sybil. (Putnam, 1989)

Schreiber in 1973 postulated that a hysterical environment will cause a person to be a “hysteric.” The “hysteric” then becomes a person with multiple personalities to escape an oppressive environment. A missing piece is why one person does this and another in the same environment may not. He cites the case of 24-year-old patient with four separate alters that were given a psychological word association test. Each of the four alters answered like they were four separate people with no leakage of a single word association. A 27-year-old patient with four alters was given a battery of neurological and psychological tests. All four selves reacted completely independently from the others. Even their EEG’s were not alike. Thirteen army psychologists could not spot the type of illness this 27-year-old patient had. It is possible that many people who suffer from amnesia may also suffer from DID. (Schreiber, 1973)

A National Institute of Mental Health survey looking at 100 DID cases reported by Putnam in 1986 found that 97% of DID patients reported significant trauma during their childhoods. Incest was reported 68% of the time, but also reported were physical abuse, extreme neglect and other factors. Coons and Milstein in 1984 reported in 20 DID patients a rate of sexual abuse in 75% of them, 50% had a history of physical abuse and they had an overall rate of 85% of child abuse in their sample. According to Putnam, as of 1989, it had not been proven that child abuse causes DID. Independent verification of abuse which may have occurred ten years or more before being reported in therapy is nearly impossible to obtain by the clinician. Kluft and Bliss have been able to verify the veracity of the abuse reports in some of their patients. Putnam believes that therapists that have worked with more than a couple of patients with DID would not doubt the existence of a causal relationship between DID and childhood trauma, mostly child abuse. Some sufferers of DID report being used in Satanic rituals. Putnam believes that the abuse suffered by patients with DID is more bizarre and sadistic than that which occurs to most victims of childhood abuse. (Putnam, 1989)

In the early to mid 1980’s, several important clinical papers were written documenting the relationship between DID and trauma, including those by Coons, Greaves and Spiegel or hypnosis and MPD (Bliss). Putnam in 1989 presented a developmental model of DID where he demonstrates that the consolidation of identity and self across behavioral states is a normal developmental part of one’s childhood, unless this process is disrupted by severe forms of trauma or other developmental issues. These disruptions cause a chronic vulnerability to personality states and the shifting states of consciousness. Under some conditions these may become organized into DID. (Brown, Scheflin & Hammond, 1998)

One theory of the etymological development of DID promoted by a vocal minority of clinicians (McHugh, Merskey and Piper) is that DID is an iatrogenic artifact of therapeutic practices that are suggestive. This theory stands in contrast to a generally accepted belief that DID is a legitimate diagnosis in the DSM-IV. Critics of DID have drawn their evidence from laboratory simulation studies where multiple role enactments that resembled the behavior of alter personalities were demonstrated in normal laboratory subjects. Promoters of the DID iatrogenesis hypothesis believe that the DID diagnosis overlaps other diagnoses, the diagnosis is unstable over time, there is no relationship between DID and trauma, its over diagnosis is encouraged due to literature on DID, its increase in incident rates is due to misdiagnosis and therapeutic suggestion, and alter behavior is shaped by the therapist. Clinicians promoting the iatrogenic view recommend that clinicians keep a treatment focus on issues in the here and now and discourage any focus on supposed childhood memories. (Brown et al., 1998)

Gleaves systematically shows the logical errors and the selective misuse of the scientific evidence proposed by the DID iatrogenic theory proponents. The DID diagnostic category was derived empirically from many studies, which gave researchers a relatively clear set of DID’s clinical features. A variety of self-report instruments that are clinically sound, such as the Dissociative Experiences Scale and the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D) demonstrate that there is a set of clinical features that are stable and valid and reliably discriminate those with DID from those with other disorders and those considered normal. DID has also been diagnosed around the world. Gleaves mentions that the DID iatrogenesis proponents rarely cite any of the diagnostic research, nor do they show that they are aware of DID’s clinically defining features. They make the logical error that multiple identity enactment is the only relevant feature of DID. Alter-like behavior may be shaped in some social interactions, like therapy, but there is no evidence to show the disorder can be created per se. (Brown et al., 1998)

Proponents of the iatrogenesis hypothesis argue that patients simulate DID to get attention, yet Gleaves cites several empirical studies that show no significant relationship between histrionic personality and other attention-seeking traits and DID. In a study done by Ross, Norton and Wozney (1989), only 27% of those with DID had hypnosis before getting the DID diagnosis. The iatrogenesis argument also doesn’t account for the fact that many patients with DID had a long history of dissociative symptoms before the DID diagnosis was made. Putnam in 1986 showed no significant differences in the clinical features of those with DID, whether hypnosis was used or not in treatment. Gleaves also states that researchers have found a strong association between forms of childhood trauma and DID. (Brown et al., 1998)

The treatment strategy recommended by proponents of the iatrogenesis of DID that therapists discourage alter behavior and recollections of abuse may be harmful. Not dealing with the condition of DID may cause interminable treatment. Simply because some of the features of DID can be role played, this does not meaningfully explain the etiology of any mental disorder. Gleaves believes the iatrogenesis model is flawed and lacks support. The role-playing theory cannot account for the primary features of DID. (Brown et al., 1998)

Several lawsuits have been brought successfully against clinicians for allegedly using suggestive practices to implant supposed false memories of abuse. Alongside a good portion of these cases there was an additional complaint that a diagnosis of DID or DDNOS was given during treatment by the defendant or accepted by the defendant if previously given. A significant part of these defendants were being sued for using treatments that were well within the scope of standard practices, such as individual psychotherapy with psychodynamic orientations. Expert testimony promoting the viewpoint that DID can be created through the suggestion of therapists extremely overgeneralizes the sparse and inadequate data available and misleads the courts it is presented in. (Brown et al., 1999)

Spanos believed that naturally occurring DID does not exist, that it is the outcome of social construction. He believed that patients were encouraged to learn the rules that are central to a process where DID is created. Spanos hypnotized two groups and didn’t hypnotize a control group, all of which were asked to role play an accused murderer. Control subjects did not adopt a different name or become amnesic. The alleged multiples created showed evidence of significant differences in psychological testing, compared to their original tests. Spanos study was replicated by Frischholz and Sachs. They found that hypnosis was not necessary to create the signs of role enactment. Their data shows that hypnosis doesn’t facilitate the making of DID-like symptoms. Additional critiques of Spanos work and socio-cognitive model include his model’s minimization of the often severe pathology connected with DID and his model’s not considering the neurobiology of DID. Sar did a study which suggested that the parietal and frontal lobes may be involved as neuromediators in DID. DID may have a neurological basis. Simulations of multiple-role enactments are not evidence that a complex disorder like DID has been created. True DID is characterized by enduring alter-personality states. (Brown et al., 1999)

Many studies have shown that the separate identities contained in patients with DID may be cognitively and physiologically distinct. Brain scans of different alters may be quite different. These differences cannot in an obvious way be intentionally simulated. These studies show that a DID diagnosis is in many cases more than role playing or feigning. Spanos, Weekes and Bertrand in 1985 demonstrated that normal college students by suggestion can be induced to show some of DID’s phenomena, including adopting a second personality. However, this does not convincingly address questions about DID’s reality. The fact that a person could give a good portrayal of a person with a broken leg does not show the nonexistence of people with broken legs. (Carson, Butcher & Mineka, 2000)

Putnam believes that a valid psychiatric diagnosis needs to fulfill three different forms of validity, content (specific and detailed description of the disorder), criterion-related (laboratory tests are consistent with the disorder) and construct validity (the disorder needs to be defined differently from other disorders). The research on DID robustly meets all three of these validity requirements. Its clinical phenomenology has been well delineated and this has been replicated by different investigators, using different methodologies, with different age groups and populations. Its core pathological process, which is dissociation, has been measured and detected by reliable scales. By looking at psychological tests, patients with DID can be distinguished from normals and other psychiatric patients. DID is also found in other cultures and can be differentiated from other disorders in these cultures. This demonstrates its cross-cultural universality. It is also one of the oldest Western diagnosis in psychiatry (Janet, Prince and Rush). DID is consistently not only found across cultures but also across time. Few other diagnoses can show this documentation. DID and other types of pathological dissociation have also been found in children. These cases have features that connect with developmental theories and data. (Putnam, 1997)

The critics of DID’s existence often appear to direct their critiques at a mass media stereotype, rather than the actual condition. Putnam wonders what the existence of DID’s critics fear the most, DID per se, or what it may say about the human condition. The existence of the first four dissociative disorders (dissociative amnesia, fugue, depersonalization disorder, DDNOS) listed in the DSM are rarely attacked. But attacks on the existence of DID/MPD have continued for more than a century. (Putnam, 1997)

To conclude, DID has had a very controversial history. Even with numerous case studies and strong data backing its existence and traumatic etiology, DID’s diagnosis has been attacked for over a century as being overdiagnosed, misdiagnosed and being created by a variety of nontraumagenic origins. Its critics have not attacked other dissociative diagnoses, nor have they criticized the connection between wartime trauma and dissociative disorders. DID itself has been misdiagnosed as other diagnoses, under diagnosed and falsely criticized as being diagnosed due to patient suggestibility throughout the last century up until almost the present time. DID has been falsely simulated (according to DSM-IV-TR diagnostic criteria) in laboratories.

The question would have to be, why, in the face of such strong scientific evidence, is there the continued denial of the existence of DID as well as its traumagenic origins? Is there a reason for the consistent denial of the scientific evidence? Could it be due to a social denial of the existence of the severe, repeated nature of child abuse that many children have to suffer through in our culture and cultures around the world? And what is the price of this denial? Will more children need to suffer the horrible abuse that survivors of DID have suffered? Or will our culture be able to accurately look at the etiology and frequency of the DID disorder, and begin to work on ways to end this suffering.


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Brown, D., Scheflin, A. W., Hammond, D. C. (1998). Memory, trauma treatment and the law. New York: W. W. Norton & Company.

Carson, R.C., Butcher, J.N., & Mineka, D. (2000). Abnormal psychology and modern life. Boston, MA: Allyn & Bacon.

Hersha, C., Hersha L., Griffis, D. & Schwartz, T. (2001) Secret weapons. Far Hills, NJ: New Horizon Press

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Author's Bio: 

Neil Brick is a licensed clinical mental health counselor and works as an advocate to stop child abuse crimes.

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