Dissociative identity disorder

**Dissociative identity disorder** (**DID**), is a mental disorder. Its old name was **multiple personality disorder**.  

The main symptom of DID is a person showing two or more "identities" or "personality states". The person behaves differently depending on which identity is in control. The second important symptom is when a person forgets important, personal things which people normally do not forget.  

A person is not diagnosed with DID if the symptoms are caused by drugs, illness, or (with children) pretending to play with imaginary friends. Most patients with DID are also diagnosed with other mental disorders.

It is not to be confused with being plural which is an identity people have of having multiple personalities in them. Plural people may or may not have DID

## Definitions
The DSM IV uses the terms "identity", "personality states" and "alternate identities" when talking about DID When talking about DID, saying someone changes personalities or alters means the person speaks and acts differently, and often responds to a different name.

Dissociation is a symptom. Most people experience normal dissociation, where they stop paying attention to what is happening around them. People with DID have pathological dissociation, which is much more serious.

## Signs and symptoms
According to the DSM-IV, the symptoms of DID are "the presence of two or more distinct identities or personality states" (which are often termed "alters"), as well as forgetting things that people normally don't forget. Also, the symptoms cannot be caused by drugs or normal childhood play. People can report having a lot of alters, or just a few. Most people diagnosed with DID have less than ten, though some people have said they have several thousand. A person diagnosed with DID cannot be diagnosed with another dissociative disorder. Because people with DID hear voices of different alters, it may be confused with schizophrenia. However, the two problems are very different and doctors can usually tell if a patient has DID or schizophrenia by asking the right questions. DID is always diagnosed by what patients tell their doctors and what the doctor thinks this means. Though people have tried diagnosing and studying DID using medical imaging or brain scanning.
### Diagnosis
The DSM uses the following criteria to diagnose DID:

## Causes
There are two main ideas about what causes DID, but there is still disagreement about which is correct. The trauma theory (that’s the theory of structural dissociation) says that DID is caused by parents or families that abuse or neglect their children. Some of these children deny the abuse is happening or pretend it is happening to someone else, and this eventually becomes a different identity or alter. Most people diagnosed with DID say they remember being abused by their parents or other caregivers when they were children. When asked about their childhood, patients with DID are more likely to say they were abused or neglected than people with any other diagnosis. However, the idea that DID develops in childhood is disputed because childhood memories are not very reliable and it is not clear if the abuse actually happened. DID is one of the most controversial mental disorders because people disagree about what causes it.   

The iatrogenic or sociocognitive model (SCM) of DID says it is created during psychotherapy when the therapist creates false memories and patients become convinced they have multiple personalities. It has also been suggested that early trauma may make children more likely to use their imaginations to pretend abuse or other painful situations are not happening, and if they enter therapy when they are older, it is easier for therapists to convince them they have DID.

## Treatment
There is no treatment approach that has been scientifically proven to work. Most therapists who treat patients with DID use several different approaches. Therapy usually lasts for several years, and does not always work. Some therapists try to reduce or eliminate the alters so the patient only has one personality, while others do not.

## Epidemiology
There have been no large-scale studies to learn how common DID is. The ISSTD says DID occurs in between 1 and 3% in the general population, and between 1 and 5% in groups of patients in hospitals.]]
Before 1900 it was thought DID was caused by spirits or ghosts who controlled people's behavior. The first case of DID described in medicine was in 1646 by the Swiss doctor Paracelsus. In 1994, the 4th edition of the DSM was published, which changed the name from "multiple personality disorder" to "dissociative identity disorder". The DSM also changed how DID was diagnosed. Many scientific articles were written about DID during the same period, though after 1995 the number of articles published every year decreased. Today there is little research on DID.

There are a lot of books, plays and movies about people with DID. In 1886 Robert Louis Stevenson published the short book *The Strange Case of Dr. Jekyll and Mr. Hyde* which was very popular. People later thought that Dr. Jekyll and Mr. Hyde were examples of someone with DID. *The Three Faces Of Eve* was a movie made in 1957 about a woman with DID. *Sybil*, a popular book about a woman with DID, was published in 1973. It was made into a movie in 1976, and a second time in 2007. A survey done in 2001 of American and Canadian psychiatrists found that there was a lot of disagreement and skepticism about diagnosing DID and if the diagnosis was based on enough good quality science.

There is also a DID community online. Online DID advocates believe that sometimes, DID should not be considered as a disease, but as multiplicity. They say multiplicity is a kind of neurodiversity, like being left-handed.

## DID in the legal system
Lawyers and doctors who work with the law also consider DID to be very controversial. People have tried to avoid going to prison for such crimes as murder and serial rape by claiming to have DID, and lawyers and judges are concerned about people pretending to have DID to avoid going to prison. The first time this happened was in 1976, and since that time most people who commit crimes and claim it was because of DID have gone to prison.

## References