Dissociative Identity Disorder: A Mysterious and Challenging Condition


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Dissociative Identity Disorder (formerly Multiple Personality)

Dissociative Identity Disorder, formerly called Multiple Personality Disorder, is a devastating condition for the individual burdened with it, but fascinating to the general public.  D.I.D. has been the focus of several books and movies, thus sensationalized and usually misunderstood.  Some medical doctors have been known to deny the existence of dissociation, much to the dismay of the patients who experience it, but with recent advancements in research and the development of treatment techniques these individuals are more frequently receiving much-needed help.

Wide Spectrum of Dissociative Disorders

Anyone who has driven alone has had the rather disturbing experience of blanking out, then realizing they have driven for some time on “automatic pilot.”  This is a normal and common dissociative experience, often the result of everyday stress.  At the other end of the spectrum is Dissociative Identity Disorder, much less common, and the result of extraordinary and overwhelming trauma, usually in childhood.  Other dissociative phenomena such as depersonalization, derealization, types of amnesia, and emotional numbing are also related to traumatic experiences, and can exist in conjunction with D.I.D., but more often exist without identity disturbance.  This article will focus on D.I.D.

Dissociation as Lack of Integration of Data

Pierre Janet, writing in the late 1800’s, was a pioneer in attempting to understand the relationship between traumatic experiences and memory disturbance.   Since that time, researchers have agreed that we construct memories from incoming data, and that we construct those memories dependent on how we integrate the new data into existing schema within our memory networks.  Dissociation is defined as:

“A disruption in the usually integrated functions of consciousness, memory, identity, or perception” (American Psychiatric Association , 2000a, p. 519)

Traumatic amnesias are well documented. For example, traffic accidents and similar acute traumas often result in partial amnesia for the event.  Being “age and dose-related,” traumatic amnesias tend to be more severe and long-lasting if the trauma occured at a very young age, and if it was chronic and inescapable.  Childhood trauma involving sexual abuse, chronic family violence, and prolonged combat exposure are most often the source of more extreme amnesia.  These prolonged experiences are so out of the normal range of experience, with no existing schema in memory networks to absorb the data, that they often remain unintegrated and inaccessible to conscious awareness.

This lack of integration of incoming data, resulting in fragmented memories, has made diagnosis and treatment of traumatic disorders very difficult historically.  Typically, individuals with disordered identity (fragmented personalities) have spent up to a decade or longer in the mental health system, receiving various diagnoses and inadequate treatment, including Electroconvulsive Therapy.

Multiple Symptoms, Multiple Diagnoses

Individuals who suffer from extreme dissociation experience a variety of mental health symptoms such as depression, panic attacks, nightmares and other sleep disturbance, somatoform disorders, and hypervigilance.  Due to the fractured personality structure, these symptoms do not exist in each state, complicating the diagnostic process, and understandably giving rise to doubt among medical practitioners.

Symptoms usually lead to a diagnosis specific to the symptom (e.g. ADD, clinical depression, hypochondriasis), especially if the individual’s memory impairment and shame prevent disclosure of traumatic events.  Lack of training and knowledge about dissociative symptoms results in inadequate screening of patients/clients, thus the most extreme of the dissociative disorders, D.I.D., often remains underdiagnosed and untreated.  Recent research and the publication of treatment guidelines by the International Society for the Study of Dissociation has improved this situation dramatically.

How Does D.I.D. Develop?

In D.I.D., alternate identity states exist, experienced as separate from one another, with discrete perceptions, memories, ages, and sometimes genders.  Individual parts can have allergies, drug sensitivities, and blood pressures that vary from part to part. It is rare for D.I.D. to develop in adulthood, when identities are usually formed; in early childhood, when the development of self and identitfy is ongoing and malleable, extreme trauma can interfere with normal development and resilience.

Childhood Trauma: Photo by Concha Garcia Hernandez

Use of specific parts of the central nervous system enhances their development.  Chronic threat in childhood results in over-activation of the primitive parts of the central nervous system (flight, flee, or freeze), however children are not capable of physically fleeing or fighting.  Fantasy play and emotional numbing are some means of adapting and escaping mentally and emotionally to stress in childhood, as is dissociation.

Dissociated behavioural states keep the overwhelming memory from awareness and allows the child to continue to develop other aspects of her identity.  Over time, these alternate states emerge when further, related trauma acts as a trigger.  This is a complex and adaptive process; adaptive during times of inescapable trauma, but maladaptive over time as various alternate states take over and significant memory gaps occur, leaving the individual vulnerable to further trauma, and feeling out of control.

Lack of attachment with the child’s primary caregivers, lack of nurturing, and lack of protection lead to vulnerability and to dissociation as children do not develop a sense of safety and security or the ability to self-soothe in times of stress.  Recent research into the effect of inadequate attachment and childhood trauma has led to experts such as Bessel van der Kolk  recommending the development of a new diagnostic category: Developmental Trauma Disorder.  One advantage of this change would be to focus attention on the root of the distress rather than the child as is the case with diagnostic categories such as Conduct Disorder.  With histories of childhood trauma, clinicians are advised to always screen for dissociative symptoms, thus increasing the possibility of the client receiving appropriate treatment or referral to someone with necessary specialized training.

Memory Fragmentation

Evidence is mounting that memory integration (or lack of) is affected by the release of high concentrations of stress hormones such as norepinephrine, epinephrine, glucocorticoids, and endogenous opiates.  Glucocorticoids are suspected of impacting hippocampal volume, a part of the brain intrinsic to integration of memories.  Ehling, Nijenhuis and Krikke (2001) discovered that female patients with confirmed D.I.D. had 25% less hippocampal volume than normal subjects.  Treatment has resulted in marked improvement in hippocampal volume.

The fracturing of personality into various states is considered to be rooted in evolutionary action systems that are further affected by psycho-social influences.   Each part emerges as a separate action system; defender against further threat, successful student, caring mother, perpetual teenager, fun-loving child, violent offender.  Each has a distinct purpose in the survival of the whole individual and usually appears spontaneously depending on the perceived need in the moment.  Due to the overwhelming and unnatural nature of childhood trauma, the beliefs intrinsic to each part are usually irrational, based in the belief that chronic danger currently exists.  The individual exists in a time warp, essentially, with dissociated parts reacting as though historical events are recent or immediate, triggering the associated terror and defensive reaction.  Something in the environment (smell, sound, image) triggers the memory at the subcortical (brainstem) level, including the deeply held irrational belief  at the basis of the terror.

Treatment of Dissociative Identity Disorder

Depending on various factors (number of parts, complexity of trauma history, current level of functioning, addictions, family and community support), treatment of D.I.D. takes several years, and is of necessity stage-based.  Therapists working with complex dissociation should have specialized training in both theory and practice, with clinical consult available.  Reliable guidance can be found at The International Society for the Study of Trauma and Dissociation, with specialized consult available for clinicians trained in Eye Movement Desensitization Reprocessing with Sandra Paulson.

Enthusiastic clinicians with inadequate training can do unintentional harm with individuals in this vulnerable population, and extreme caution is recommended.


Kaplan, H., Sadock, B.  Synopsis of Psychiatry. (1991).Williams and Wilkins.

Van der Hart, O., Friedman, B.  Dissociation. (1989). 2(1)3-16.

Van der Kolk, B., Fisler, R.  Dissociation and the Fragmentary Nature of  Traumatic Memories:  Overview and Exploratory StudyHarvard Medical School Department of Psychiatry.  Originally published in Journal of Traumatic Stress, 1995, 8(4), 505-525. Accessed September 5, 2011.

Steele, K., Van der Hart, O., Nijenhuis, E.  Phase-Oriented Treatment of Structural Dissociation in Complex Traumatization:  Overcoming Trauma-Related Phobias.  (2005) Journal of Trauma & Dissociation, Vol. 6(3).

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