Dissociative identity disorder
Synonyms: Multiple personality disorder

# Overview
Dissociative Identity Disorder (DID), as defined by the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-V-TR), is a mental condition whereby a single individual evidences two or more distinct identities or personalities, each with its own pattern of perceiving and interacting with the environment. The diagnosis requires that at least two personalities routinely take control of the individual's behavior and that there is associated memory loss that goes beyond normal forgetfulness, often referred to as losing time or acute Dissociative Amnesia. The symptoms of DID do not necessarily need to be the direct result of substance abuse or a more general medical condition in order to be diagnosed. DID was originally called Multiple Personality Disorder (MPD), and as referenced above, that name remains in the International Statistical Classification of Diseases and Related Health Problems. It is also commonly mispronounced "Disassociative Identity Disorder", and the primary symptom erroneously called "disassociation".
This condition is not the same as schizophrenia (DSM-IV Schizophrenia and Other Psychotic Disorders), as is a common misconception. The term schizophrenia comes from root words for "split mind," however it refers to a fracture in the normal functioning of the brain rather than the personality.
Dissociation is a symptom of several psychiatric disorders, including Borderline Personality Disorder (DSM-IV Personality Disorders 301.83), Post-traumatic stress disorder (DSM-IV Anxiety Disorders 309.81), and Complex Post Traumatic Stress Disorder among others.
As a diagnosis, DID remains controversial. For many years DID was regarded as a North American phenomenon with the bulk of the literature still arising there. However, research demonstrates a lack of consensus belief in the validity of DID amongst North American psychiatrists. Practitioners who do accept DID as a valid disorder have produced an extensive literature with some of the more recent papers originating outside North America.

# Historical perspective
- A prominent curiosity of spiritualism, parapsychology and hypnosis continued throughout the 19th and early 20th centuries, relating to Locke's views that there was an association of ideas requiring the coexistence of feelings with awareness of the feelings.
- Hypnosis, introduced by Mesmer and de Puysegur in the late 1700s, opposed Locke's association of ideas. Hypnotists observed second personalities emerging during hypnosis and wondered how two minds could coexist. Hence early cases of what would now be diagnosed as DID appeared and were treated by hypnosis.
- The 19th century saw a number of increasingly sophisticated reported cases of multiple personalities which Rieber estimated would be close to one hundred.
- Epilepsy was seen as a factor in some cases. This connection is still upon discussion today.
- By the late 19th century there was a realization that emotionally traumatic experiences may cause long-term disorders which may manifest with a variety of symptoms. Charcot then introduced his ideas of the impact of nervous shocks as a cause for a variety of neurological conditions. As one of Charcot's students, Janet took these ideas and went on to develop his own theories of dissociation. 
- In the early 20th century interest in dissociation and MPD waned for a number of reasons. After Charcot's death in 1893 many of his "hysterical" patients were exposed as frauds and Janet's association with Charcot tarnished his theories of dissociation.
- In 1910, Bleuler introduced the term "schizophrenia" to replace "dementia praecox" and a review of the Index Medicus from 1903 through 1978 showed a dramatic decline in the number of reports of multiple personality after the diagnosis of schizophrenia "caught on."
- The public however was exposed to psychological ideas which took their interest. Mary Shelley's Frankenstein, Robert Louis Stevenson's Strange Case of Dr Jekyll and Mr Hyde and many short tales by Edgar Allan Poe, had a disturbing impact but it was not until the 1957 publication of the book The Three Faces of Eve, and the popular movie which followed it, that the American public's interest in multiple personality was revived.
- In 1974 the highly influential book Sybil was published and six years later the diagnosis of Multiple Personality Disorder was included in the DSM.
- As media coverage spiked, diagnoses climbed. There were 200 reported cases of MPD from 1880 to 1979, and 20,000 from 1980 to 1990. Acocella reports that 40,000 cases were diagnosed from 1985 to 1995.
- The majority of diagnoses are made in North America, particularly the United States, and in English-speaking countries more generally with reports recently emerging from other countries.

# Defining the terms
- Dissociation at its simplest means that "two or more mental processes or contents are not associated or integrated." This definition assumes that these elements should normally be associated or integrated in conscious awareness, memory, or identity. 
- The DSM-IV characterizes dissociation as "disruption in the usually integrated functions of consciousness, memory, identity, or perception of the environment" while the ICD-10 defines it as "partial or complete loss of the normal integration between memories of the past, awareness of identity and immediate sensations, and control of bodily movements."
- To dissociate is to separate the association of one thing with another.
- Multiple personalities occur when the identity of a person dissociates to the extent that they have separate existences with their own "identities, life histories, and enduring patterns of perceiving, thinking about and relating to the environment which is distinct from the habitual personality's mode of being in the world."
- Alter derives from alter ego and means one of the individual personalities in a person with multiple personalities.

# Defining the controversy
- One of the primary reasons for the ongoing re-categorization of this condition is that there were once so few documented cases (research in 1944 showed only 76) of what was once referred to as multiple personality.
- Dissociation is recognized as a symptomatic presentation in response to trauma, extreme emotional stress, and, as noted, in association with emotional dysregulation and borderline personality disorder.
- Often regarded as a dynamic sub-symptomatology, it has become more frequent as an ancillary diagnosis, rather than a primary diagnosis.

## The DSM re-dress
- There is considerable controversy over the validity of the multiple personality controversy profile as a diagnosis. Unlike the more empirically verifiable mood and personality disorders, dissociation is primarily subjective for both the patient and the treatment provider. The relationship between dissociation and multiple personality creates conflict regarding the MPD diagnosis.
- While other disorders require a certain amount of subjective interpretation, those disorders more readily present generally accepted, objective symptoms. The controversial nature of the dissociation hypothesis is shown quite clearly by the manner in which the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM) has addressed, and re-dressed, the categorization over the years.
- The second edition of the DSM referred to this diagnostic profile as Multiple Personality Disorder. The third edition grouped Multiple Personality Disorder in with the other four major Dissociative Disorders. The current edition, the DSM-IV-TR, categorizes the disorder as Dissociative Identity Disorder. The ICD-10 (International Statistical Classification of Diseases and Related Health Problems) continues to refer to the condition as Multiple Personality Disorder.

## The MPD/DID epidemic in North America
- Parisin a review offered four possible causes for the sudden increase in people diagnosed with MPD/DID:
- The result of therapist suggestions to easily swayed people, much as Charcot's hysterics acted in accordance with his expectations.
- Psychiatrists' past failure to recognise dissociation being redressed by new training and knowledge.
- Dissociative phenomena are actually increasing, but this increase only represents a new form of an old and protean entity: "hysteria."
- Powerful psychosocial forces are changing the psychological balance of individuals so as to make dissociative experiences more common.
- Paris suggests that the first possible cause is the most likely.

## Other positions
- The debate over the validity of this condition, whether as a clinical diagnosis, a symptomatic presentation, a subjective misrepresentation on the part of the patient, or a case of unconscious collusion on the part of the patient and the professional is considerable (see multiple personality controversy).
- There is very little in the way of objective, quantifiable evidence for describing the disorder. This makes the disorder itself subjective, as well as its diagnosis.
- The main points of disagreement are as follows:
- Whether MPD/DID is a real disorder or simply a fad.
- If it is real, is the appearance of multiple personalities real or delusional?
- If it is real, should it be defined in psychoanalytic terms?
- Can it and should it be cured?
- Who should primarily define the experiencetherapists, or those who believe that they have multiple personalities?
- Skeptics claim that people who present with the appearance of alleged multiple personality may have learned to exhibit the symptoms in return for social reinforcement.

# Classification
- There is no established system for the classification of dissociative identity disorder.

# Pathophysiology
- Reviews of the literature have discussed the findings of various psychophysiologic investigations of DID. Many of the investigations include testing and observation in one person but with different alters. Different alter states show distinct physiological markers. EEG studies have shown distinct differences between alters, findings another study failed to replicate.
- Another study concluded that the differences involved intensity of concentration, mood changes, degree of muscle tension, and duration of recording, rather than some inherent difference between the brains of persons with multiple personalities and those of normal persons. One EEG study comparing DID with hysteria showed differences between the two diagnoses.
- A proposed link between epilepsy and DID has been disputed by a number of authors.
- Some brain imaging studies have shown differing cerebral blood flow with different alters while another has failed to replicate this finding. 
- A different imaging study showed that findings of smaller hippocampal volumes in patients with a history of exposure to traumatic stress and an accompanying stress-related psychiatric disorder were also demonstrated in DID. This study also found smaller amygdala volumes.
- Studies have demonstrated various changes in visual parameters between alters.
- One twin study showed hereditable factors were present in DID.

# Causes/etiology
- Although many experts dispute the existence of this controversial diagnosis, DID has been attributed by some to the interaction of several factors:
Overwhelming stress
Dissociative capacity (including the ability to uncouple one's memories, perceptions, or identity from conscious awareness)
The enlistment of steps in normal developmental processes as defenses
The lack of sufficient nurturing and compassion in response to hurtful experiences or lack of protection against further overwhelming experiences during childhood.
Children are not born with a sense of a unified identity  it develops from many sources and experiences. In overwhelmed children, its development is obstructed, and many parts of what should have blended into a relatively unified identity remain separate.
North American studies show that 97 to 98% of adults with dissociative identity disorder report abuse during childhood and that abuse can be documented for 85% of adults and for 95% of children and adolescents with dissociative identity disorder and other closely related forms of Dissociative Disorders. Although these data establish childhood abuse as a major cause among North American patients (in some cultures, the consequences of war and disaster play a larger role), they do not mean that all such patients were  abused or that all the abuses reported by patients with dissociative identity disorder really happened. Some aspects of some reported abuse experiences may prove to be inaccurate. Patients may have also experienced important early losses (such as death of a parent), serious medical illness, or other very stressful events. Parents helping people through these times can act as a preventative measure.
Human development requires that children be able to integrate complicated and varying types of information and experiences successfully. As children achieve cohesive, complex appreciations of themselves and others, they go through phases in which different perceptions and emotions are kept segregated. Each developmental phase may be used to generate different selves.
Not every child who experiences abuse or major loss or trauma has the capacity to develop multiple personalities. Patients with dissociative identity disorder can be easily hypnotized. This capacity, closely related to the capacity to dissociate, is thought to be a factor in the development of the disorder. However, most children who have these capacities also have normal adaptive mechanisms, and most are sufficiently protected and soothed by adults to prevent development of dissociative identity disorder.
- Overwhelming stress
- Dissociative capacity (including the ability to uncouple one's memories, perceptions, or identity from conscious awareness)
- The enlistment of steps in normal developmental processes as defenses
- The lack of sufficient nurturing and compassion in response to hurtful experiences or lack of protection against further overwhelming experiences during childhood.
Children are not born with a sense of a unified identity  it develops from many sources and experiences. In overwhelmed children, its development is obstructed, and many parts of what should have blended into a relatively unified identity remain separate.
North American studies show that 97 to 98% of adults with dissociative identity disorder report abuse during childhood and that abuse can be documented for 85% of adults and for 95% of children and adolescents with dissociative identity disorder and other closely related forms of Dissociative Disorders. Although these data establish childhood abuse as a major cause among North American patients (in some cultures, the consequences of war and disaster play a larger role), they do not mean that all such patients were  abused or that all the abuses reported by patients with dissociative identity disorder really happened. Some aspects of some reported abuse experiences may prove to be inaccurate. Patients may have also experienced important early losses (such as death of a parent), serious medical illness, or other very stressful events. Parents helping people through these times can act as a preventative measure.
Human development requires that children be able to integrate complicated and varying types of information and experiences successfully. As children achieve cohesive, complex appreciations of themselves and others, they go through phases in which different perceptions and emotions are kept segregated. Each developmental phase may be used to generate different selves.
Not every child who experiences abuse or major loss or trauma has the capacity to develop multiple personalities. Patients with dissociative identity disorder can be easily hypnotized. This capacity, closely related to the capacity to dissociate, is thought to be a factor in the development of the disorder. However, most children who have these capacities also have normal adaptive mechanisms, and most are sufficiently protected and soothed by adults to prevent development of dissociative identity disorder.
- Children are not born with a sense of a unified identity  it develops from many sources and experiences. In overwhelmed children, its development is obstructed, and many parts of what should have blended into a relatively unified identity remain separate.
- North American studies show that 97 to 98% of adults with dissociative identity disorder report abuse during childhood and that abuse can be documented for 85% of adults and for 95% of children and adolescents with dissociative identity disorder and other closely related forms of Dissociative Disorders. Although these data establish childhood abuse as a major cause among North American patients (in some cultures, the consequences of war and disaster play a larger role), they do not mean that all such patients were  abused or that all the abuses reported by patients with dissociative identity disorder really happened. Some aspects of some reported abuse experiences may prove to be inaccurate. Patients may have also experienced important early losses (such as death of a parent), serious medical illness, or other very stressful events. Parents helping people through these times can act as a preventative measure.
- Human development requires that children be able to integrate complicated and varying types of information and experiences successfully. As children achieve cohesive, complex appreciations of themselves and others, they go through phases in which different perceptions and emotions are kept segregated. Each developmental phase may be used to generate different selves.
- Not every child who experiences abuse or major loss or trauma has the capacity to develop multiple personalities. Patients with dissociative identity disorder can be easily hypnotized. This capacity, closely related to the capacity to dissociate, is thought to be a factor in the development of the disorder. However, most children who have these capacities also have normal adaptive mechanisms, and most are sufficiently protected and soothed by adults to prevent development of dissociative identity disorder.

# Differential diagnosis
- Dissociative identity disorder must be differentiated from:
- Bipolar disorder
- Factitious disorder
- Functional neurological symptom disorder (conversion disorder)
- Major depressive disorder
- Other dissociative disorders
- Personality disorders
- Post traumatic stress disorder
- Psychotic disorder
- Seizure disorders
- Substance-induced disorders

# Epidemiology and demographics

## Prevalence
- The prevalence of dissociative identity disorder is 1,500 per 100,000 (1.5%) among the U.S. adult population.

## Gender
- The prevalence of dissociative identity disorder among males is 1,600 per 100,000 (1.6%) of the overall population and among females is 1,400 per 100,000 (1.4%) of the overall population.

## Region
- Reports of the prevalence of the disorder in other locations of the world are often given by advocates for the condition and figures from psychiatric populations (inpatients and outpatients) show a wide diversity from different countries:
India (0.015% per year)
Switzerland (0.05%-0.1%)
China (0.4%)
Germany (0.9%)
The Netherlands (2%)
U.S. (6%, Approx., 6-8%, 10%)
Turkey (14%)
- India (0.015% per year)
- Switzerland (0.05%-0.1%)
- China (0.4%)
- Germany (0.9%)
- The Netherlands (2%)
- U.S. (6%, Approx., 6-8%, 10%)
- Turkey (14%)
- Figures from the general population show less diversity:
China (0%)
Turkey (0.4% for a general sample and 1.1% for a female sample)
Canada (1%)
- China (0%)
- Turkey (0.4% for a general sample and 1.1% for a female sample)
- Canada (1%)

# Risk Factors
- Interpersonal, physical or sexual abuse
- Traumatic experiences during childhood, including:
- Terrorism
- Childhood prostitution
- War
- Medical or surgical procedures.

# Natural history, prognosis and complications

## Natural History
- Dissociative identity disorder can appear at any age.
- The disorder is usually associated with memory, attachment or concentration problems in children as the disease doesn't present identity changes during childhood. It can be confused with adolescent turmoil during adolescence.
- When diagnosed in older patients, these usually have symptoms associated with mood changes such as paranoia, obsessive-compulsive disorder, mood disorders associated with a psychotic disease.
- DID does not disappear suddenly, although the severity of symptoms may change.  A patient's progress can be divided in three groups.
The first group tend to have dissociative and post-traumatic symptoms, function well and recover completely with particular treatment.
The second group have dissociative symptoms, usually mixed with symptoms from personality disorders, mood disorders, eating disorders, or substance abuse disorders. Because treatment may be less successful, longer, or more difficult, improvement is slower.
The third group have severe comorbid psychopathology, and may be emotionally attached to their supposed abusers.  This group requires long-term treatment to manage the symptoms rather than to achieve integration.
- The first group tend to have dissociative and post-traumatic symptoms, function well and recover completely with particular treatment.
- The second group have dissociative symptoms, usually mixed with symptoms from personality disorders, mood disorders, eating disorders, or substance abuse disorders. Because treatment may be less successful, longer, or more difficult, improvement is slower.
- The third group have severe comorbid psychopathology, and may be emotionally attached to their supposed abusers.  This group requires long-term treatment to manage the symptoms rather than to achieve integration.

## Prognosis
- Poor prognosis is associated with:
Permanent abuse
Association with other psychiatric disorders
New traumatizing experience
Severe medical illness and delay in appropriate medical treatment for the disorder
- Permanent abuse
- Association with other psychiatric disorders
- New traumatizing experience
- Severe medical illness and delay in appropriate medical treatment for the disorder

# Diagnosis
- If symptoms seem to be present, the patient should initially be evaluated by performing a complete medical history and physical examination.
- Diagnostic tests, such as X-rays and blood tests may be used to rule out physical illness or medication side effects as the cause of the symptoms.
- Certain conditions, including brain diseases, head injuries, drug and alcohol intoxication, and sleep deprivation, can lead to symptoms similar to those of Dissociative Disorders, including Dissociative Amnesia.
- If no physical illness is found, the patient might be referred to a psychiatrist or psychologist who may use specially designed interviews and personality assessment tools to evaluate a person for a Dissociative Disorder.

## Diagnostic criteria

### DSM-V Diagnostic Criteria for Dissociative Identity Disorder
- A. Identity disruption which main characteristic is the presence of more then one personality states, sometimes defined as an possession experience in some cultures.  The alteration is associated with behavior changes, affect, consciousness, memory and cognition changes or loss in the agency or self sense.  These changes can be self-reported or observed by another person.
OR
- B. Presence of recurrent lack of memory of everyday events, traumatic events and/or personal information which can be associated with common forgetfulness.
AND
- C. A clinically significant impairment in the patients normal life is caused by the disorder's symptoms.
AND
- D. The disorder is not associated to a normal cultural or religious practice which is accepted by the community.  In children, the presence of imaginary playmates does not explain the symptoms.
AND
- E. The consumption of substances or other diseases does not explain the symptoms.

## Symptoms
- Patients often exhibit a wide variety of symptoms that can resemble other neurologic and psychiatric disorders, such as anxiety disorders, personality disorders, schizophrenic, mood psychosis and seizure disorders.
- Symptoms of this particular disorder can include:
Depression
Nightmares
Anxiety (sweating, rapid pulse, palpitations)
Phobias
Panic attacks
Fluctuating levels of function, from highly effective to disabled
Time distortions, time lapse, and Dissociative Amnesia
Sexual dysfunction
Eating disorders
Post traumatic stress
Suicidal preoccupations and attempts
Episodes of self-mutilation
Psychoactive substance use/abuse
- Depression
- Nightmares
- Anxiety (sweating, rapid pulse, palpitations)
- Phobias
- Panic attacks
- Fluctuating levels of function, from highly effective to disabled
- Time distortions, time lapse, and Dissociative Amnesia
- Sexual dysfunction
- Eating disorders
- Post traumatic stress
- Suicidal preoccupations and attempts
- Episodes of self-mutilation
- Psychoactive substance use/abuse
- Other symptoms may include:
Depersonalization, which refers to feeling unreal, removed from one's self, and detached from one's physical and mental processes. The patient feels like an observer of their life and may actually see themselves as if they were watching a movie.
Derealization refers to experiencing familiar persons and surroundings as if they were unfamiliar and strange or unreal.
Again, doctors must be careful not to assume that a client has MPD or DID simply because they exhibit some or all of these symptoms. In order for DID to be diagnosed, there must be two or more distinctly present personalities.
- Depersonalization, which refers to feeling unreal, removed from one's self, and detached from one's physical and mental processes. The patient feels like an observer of their life and may actually see themselves as if they were watching a movie.
- Derealization refers to experiencing familiar persons and surroundings as if they were unfamiliar and strange or unreal.
- Again, doctors must be careful not to assume that a client has MPD or DID simply because they exhibit some or all of these symptoms. In order for DID to be diagnosed, there must be two or more distinctly present personalities.
- Persons with dissociative identity disorder are often told of things they have done but do not remember and of notable changes in their behavior. They may discover objects, productions, or handwriting that they cannot account for or recognize; they may refer to themselves in the first person plural (we) or in the third person (he, she, they); and they may have amnesia for events that occurred between their mid-childhood and early adolescence. Amnesia for earlier events is normal and widespread.

## Diagnostic Problems Associated with Culture
- Symptoms such as seizures, paralysis or sensory loss may be common among certain cultures. Possession is common in some settings such as rural areas or a few religions in the United States and Europe, therefore the symptoms and different identities could be associated with different demons that have possessed the patient.

## Diagnostic Problems Associated with Gender
- The diagnosis is harder to make among adult males as these patients tend to hide their symptoms and deny traumatic experiences. On the other had, the disease is more common in boys than girls. The presentation in females is usually more related with acute dissociative states such as flashbacks, conversion disorders, hallucinations, self mutilation and amnesia. Males have usually more violent or criminal behaviors which are triggered by stressful states such as prison, sexual or physical assaults and war.

## Laboratory Findings
- There are no diagnostic laboratory findings associated with dissociative identity disorder.

## Imaging
- Imaging studies are usually not indicated in diagnosis of dissociative identity disorder.

# Treatment/management
- The most common approach to treatment aims to relieve symptoms, to ensure the safety of the individual, and to reconnect the different identities into one well-functioning identity. There are, however, other equally respected treatment modalities that do not depend upon integrating the separate identities.
- Treatment also aims to help the person safely express and process painful memories, develop new coping and life skills, restore functioning, and improve relationships. The best treatment approach depends on the individual and the severity of his or her symptoms. Treatment is likely to include some combination of the following methods:
Psychotherapy: This kind of therapy for mental and emotional disorders uses psychological techniques designed to encourage communication of conflicts and insight into problems.
Cognitive therapy: This type of therapy focuses on changing dysfunctional thinking patterns.
Medication: There is no medication to treat Dissociative Disorders themselves. However, a person with a Dissociative Disorder who also suffers from depression or anxiety might benefit from treatment with a medication such as an antidepressant or anti-anxiety medicine.
Family therapy: This kind of therapy helps to educate the family about the disorder and its causes, as well as to help family members recognize symptoms of a recurrence.
Expressive therapy such as art therapy or music therapy: These therapies allow the patient to explore and express his or her thoughts and feelings in a safe and creative way.
Clinical hypnosis: This is a treatment technique that uses intense relaxation, concentration and focused attention to achieve an altered state of consciousness or awareness
Behavior therapy: As an increasing number of therapists view DID as iatrogenic, or caused by reinforcing treatment teams, new approaches have emerged. Current standards of care may involve requiring the patient respond to a single name, and refusing to speak with the patient if she or he is a different sex, age, or person than initially presented. As the patient begins to respond more consistently to a single name, and speak in the first person, more traditional therapy for trauma may begin. Though some dislike this approach or criticize it as disrespectful of the client, it is highly effective, and many published accounts confirm this approach. See Kohlenberg & Tsai's "Functional Analytic Psychotherapy" (1991) for a more detailed explanation of this approach.
Ego-state therapy: Ego-state therapy is used to help non-dissociative individuals resolve conflicts among different parts of themselves (i.e. ego states); since DID is an extreme differentiation among ego states, many therapists find the approach useful in working with dissociative clients.
- Psychotherapy: This kind of therapy for mental and emotional disorders uses psychological techniques designed to encourage communication of conflicts and insight into problems.
- Cognitive therapy: This type of therapy focuses on changing dysfunctional thinking patterns.
- Medication: There is no medication to treat Dissociative Disorders themselves. However, a person with a Dissociative Disorder who also suffers from depression or anxiety might benefit from treatment with a medication such as an antidepressant or anti-anxiety medicine.
- Family therapy: This kind of therapy helps to educate the family about the disorder and its causes, as well as to help family members recognize symptoms of a recurrence.
- Expressive therapy such as art therapy or music therapy: These therapies allow the patient to explore and express his or her thoughts and feelings in a safe and creative way.
- Clinical hypnosis: This is a treatment technique that uses intense relaxation, concentration and focused attention to achieve an altered state of consciousness or awareness
- Behavior therapy: As an increasing number of therapists view DID as iatrogenic, or caused by reinforcing treatment teams, new approaches have emerged. Current standards of care may involve requiring the patient respond to a single name, and refusing to speak with the patient if she or he is a different sex, age, or person than initially presented. As the patient begins to respond more consistently to a single name, and speak in the first person, more traditional therapy for trauma may begin. Though some dislike this approach or criticize it as disrespectful of the client, it is highly effective, and many published accounts confirm this approach. See Kohlenberg & Tsai's "Functional Analytic Psychotherapy" (1991) for a more detailed explanation of this approach.
- Ego-state therapy: Ego-state therapy is used to help non-dissociative individuals resolve conflicts among different parts of themselves (i.e. ego states); since DID is an extreme differentiation among ego states, many therapists find the approach useful in working with dissociative clients.

# Prevention/screening
- Strategies to prevent the development of DID depend upon how the etiology of the disorder is perceived. Early childhood trauma is frequently attributed as an etiology of DID, and so from this viewpoint, prevention of childhood trauma should reduce the incidence of DID. Those who believe that DID is often caused by suggestions from the clinician to suggestible people, caution clinicians against contributing to the diagnosis.

# Future and Investigational Therapies
- Neuroimaging is a novel method of discovering the relationship between DID and brain structure, which many hope will uncover the effect of DID on the brain, and possible medication for DID.