Biomedical Research Health and Disease Neuroscience

Dissociative Identity Disorder: Exploring the Reality Behind Having Multiple Personalities

Dissociative Identity Disorder (DID) is a frequently misunderstood condition, and some do not even believe that it exists. This article discusses the biology of the condition itself, as well as how it impacts individuals and the tragic circumstances that lead to it.


Multiple personality disorder is the term that was previously used to describe what is now known as dissociative identity disorder (DID). This is a psychological condition which the brain instigates as a method of self-preservation and is often the result of prolonged and habitual abuse. DID is, according to WebMD, “a severe form of dissociation”1 where an individual becomes mentally disconnected from their thoughts, memories, and even their self-identity. Although severe, this is one way that the human body tries to protect itself from traumatic and difficult situations – by shutting the primary consciousness away and creating other consciousnesses to deal with the present trauma. When each alteration is in control of the individual’s body, this is referred to as fronting. According to the American Psychiatric Association2, approximately 90% of those in Europe, Canada, and the United States suffering from DID have experienced abuse and neglect during childhood. Sufferers of DID have at least two separate and distinct personalities or consciousnesses, and the other personalities cannot remember what happened when they were not the fronting consciousness.

DID is an example of a dissociative disorder, and sufferers of such disorders perpetually feel disconnected from their reality. Approximately 2% of the US population have dissociative disorders3, and women are more likely to have such conditions than men. The three primary dissociative disorders are dissociative identity disorder (DID), derealisation disorder, and dissociative amnesia. Post-traumatic stress disorder (PTSD) and acute stress disorder share similar symptoms with dissociative disorders – including memory loss and depersonalization – but are not considered to fully be dissociative disorders in their own right.

An article published in the International Journal of Social Psychiatry4 entitled “Dissociative Disorders in a Psychiatric Institution in India – a Selected Review and Patterns over a Decade” discusses research into DID. The purpose of this study was to examine patterns of DID sufferers across ten years and included inpatients and outpatients who attended a psychiatric hospital between the years 1999 and 2008. The research discovered that between 1.5 and 15.0 per 1,000 outpatients were diagnosed with DID, while between 1.5 and 11.6 per 1,000 of the inpatients were diagnosed. This review concluded by stating that “dissociative motor disorder and dissociative convulsions are the most common disorders” and that DID is especially under-diagnosed outside of Western regions.

What Causes DID?

Although there is no single definitive cause of DID, the main factor for this condition is severe and repeated abuse – including physical, emotional, and sexual abuse. This abuse often will begin in childhood, and, compounded with the fact that the child often does not have a safe refuge from such abuse because it is typically, though not always, carried out by a family member, can cause the child to develop DID. In rarer cases, a person can develop DID due to experiencing a violent and traumatic event, such as living in a combat zone.

Signs and Symptoms

For a person to be categorized as having DID, they have to have at least two distinct personalities. The predominant identity of the individual is known as the ‘core’ identity, and the personalities created are the ‘alters’5. Someone with DID can have many alters, possibly over 100. These alters, if there are many, tend to vary in age, gender, ethnicities, and characters even within a single person – and for some people with DID their alters are able to interact with one another.

The main symptom of DID is sudden and involuntary transitions between these alters. As a result, this can mean that the core identity has many long-term gaps in their memory, as they can only remember details from when they are fronting. Self-harm and suicide attempts are unfortunately very prevalent amongst DID sufferers, and over 70% of outpatients with DID have attempted suicide at least once3.

6Some common symptoms of DID include sudden flashbacks, feeling detached from one’s own body/out-of-body experiences, hallucinations, and inability to be aware of one’s surroundings – for example, finding yourself in a place with no memory of how you got there. Long periods of memory loss are also typical for DID sufferers, and this is known as dissociative amnesia – which is a type of memory loss that is greater than forgetfulness. Dissociative fugue is an episode of amnesia that can cause the person to not remember personal information or to experience emotional detachment7. In addition to these symptoms of DID, sufferers of this condition may also endure mood swings, anxiety, panic attacks, unexplained phobias, insomnia, night terrors, migraines, severe pain anywhere on the body, sexual dysfunction, and the increased likelihood of developing eating disorders.

Not only does DID cause intense emotional and psychological difficulty for an individual with the condition, but also it can physically change the brain. A paper published in The American Journal of Psychiatry8 examined the results of a study involving 38 women. Fifteen (15) of these women had DID, while the other 23 did not have DID, nor any other psychiatric condition. Each woman underwent MRI scanning to measure the volumes of their hippocampus, which controls memory, and amygdala, which controls emotions. The results were compared between these two groups and showed that the volume of the hippocampus was 19.2% smaller for those with DID. The volume of the amygdala was 31.6% smaller in the DID patients too. Overall, this suggests that people with DID will generally have a lower hippocampal and amygdalar volume compared to people who do not have DID. This leads to impacts on memory and emotions, which is common for sufferers of DID – who typically have long periods of memory loss or significant gaps in their memory, in addition to frequent mood swings and swiftly changing emotions.

In a paper published in the National Library of Medicine9, a study was carried out to measure hippocampal volume in 21 women who had been severely sexually abused during childhood, as well as 21 women who had not previously been abused. Again, magnetic resonance imaging (MRI) was used to determine the hippocampal volume for each of the 42 women, and the results of this study showed that the left-sided hippocampal volume was, on average, 5% smaller in the women who were sexually abused compared to the women who had not been. While the same test was carried out on the right-sight hippocampus for each woman, the article states, “hippocampal volume was also smaller on the right side, but this failed to reach statistical significance.” The results of this study show how abuse – of any kind, but in this research, it was specifically sexual abuse – can physically damage the brain, as it tries to protect the individual by having extensive gaps in their memory. As discussed previously, sustained abuse can cause DID to manifest in the individual, as sufferers of this condition present with similar changes to the hippocampal volume.

Intervention and Treatment

Like other psychological conditions, there is no cure for DID, but there are several treatment methods that have proved effective. Treatment for DID can take several years, and the most common method is psychotherapy. Throughout this process, the aim is to work with the patient so that their individual alters can merge to form a single, cohesive identity5. This is an arduous process, as it involves the patient working through the trauma and/or abuse that caused them to develop DID in the first place. Family therapy can also be helpful for sufferers of DID, as it can educate friends and family members about the difficulties of living with DID and how best to support that person. Less frequently, clinical hypnosis can be used as a possible treatment method for DID, in which patients can access repressed memories that they experienced as one of their alters and so cannot remember when any other alter is fronting6. Furthermore, cognitive behavioral therapy is another commonly used method in an attempt to treat DID.


The American Psychiatric Association led a question-and-answer panel with an expert of psychiatry: Dr. David Spiegel, Professor and Associate Chair of Psychiatry & Behavioural Sciences at Stanford University School of Medicine10. When he was asked the question, “are people with dissociative identity disorder often misdiagnosed?” Dr. Spiegel said: “they are sometimes misdiagnosed as having schizophrenia. Another common misdiagnosis is borderline personality disorder.” Later in the article, Dr. Spiegel says, “typically those with dissociative identity disorder experience symptoms for six years or more before being correctly treated.” This shows not only how difficult it is to acquire treatment but, even when treatment is given it can frequently be based on a misdiagnosis. If a person with DID is misdiagnosed as having schizophrenia, they may be prescribed antipsychotic medications, and their emotions will be dulled when they take this. This will lead to further increases in this antipsychotic medication on the belief that it is an effective treatment for the individual. Dr. Spiegel remarks that “dissociation is a common coping mechanism,” saying that “many rape victims experience the crime as though they were floating above their bodies.” While dissociation is a natural human response to a traumatic event, it is when this trauma is sustained and repeated that this dissociation can develop into DID.

Individuals’ Stories

Jeni Haynes is a woman who has DID and has over 2500 distinct personalities/alters – though only six predominant ones. Jeni developed DID due to her intensely traumatic childhood, where she was subjected to horrific physical and sexual abuse from her father, Richard Haynes. In the trial against Richard Haynes for this abuse, Jeni testified through her multiple personalities, allowing each one to front her in turn. After the core personality of Jeni Haynes, there was Symphony, a four-year-old girl who endured much of the abuse – and described by Jeni to be her most significant alter. Jeni addressed the court, telling them: “Symphony intended to testify in court for the whole thing. When my father raped Jennifer Haynes, he raped Symphony.” Jeni’s other alters included an eleven-year-old boy called Judas and a 17-year-old boy called Muscles11. This trial was the first trial in Australia where an individual was allowed to provide evidence through their alters. While Richard Haynes was convicted, that does not mean that Jeni has a normal life now. Her DID causes her struggle every day, and in her victim impact statement, she said, speaking about her and all of her different alters: “we have to hide our multiplicity and strive for a consistency in behavior. Having 2,500 different voices, opinions and attitudes is extremely hard to manage”12.

Another example of an individual’s struggle with DID is that of a 25-year-old soldier. In an article written by the American Psychiatric Association13, she is referred to only as “Sandra”, which is a pseudonym to maintain confidentiality. Sandra was hospitalized due to her sudden behavioral changes and episodes of acute memory loss. As she underwent clinical hypnosis, it was discovered that she had a series of significantly large gaps in her memory, and she was also found to have swift and severe changes in her emotions. She then began to have psychotherapy, where she worked through the memories of sexual abuse she had endured since the age of 11. Sandra was diagnosed with DID, and now she continues to have psychotherapy as well as take anti-depressants. She reportedly rarely dissociates and has now been able to establish stable relationships.


To conclude, dissociative identity disorder (DID) is a psychiatric condition that can present immense difficulty to those with it, as they can feel completely disconnected from their surroundings – and it can be terrifying when individuals cannot remember what has happened to them and feel like they do not have autonomy over their own body. Furthermore, DID is hugely underdiagnosed or misdiagnosed and can mean that the treatment people need – which is already a lengthy process of many years at least – is delayed. There needs to be more information about DID, as some do not believe it is even an actual condition. Educating people about DID can mean that they can recognize if their friends or families show signs of this condition and can potentially aid them to attain treatment and support faster than if they waited to do so themselves.

Samara Macrae, Youth Medical Journal 2022


1.   WebMD: “Dissociative Identity Disorder (Multiple Personality Disorder) –

2.   American Psychiatric Association: “What Are Dissociative Disorders?” –

3.   Cleveland Clinic: “Dissociative Disorders” –

4.   International Journal of Social Psychiatry: “Dissociative Disorders in a Psychiatric Institution in India – a Selected Review and Patterns over a Decade” –

5.   Cleveland Clinic: “Dissociative Identity Disorder (Multiple Personality Disorder)” –

6.   American Association for Marriage and Family Therapy: “Dissociative Identity Disorder” –

7.   Healthline: “Dissociative Identity Disorder” –

8.   The American Journal of Psychiatry: “Hippocampal and Amygdalar Volumes in Dissociative Identity Disorder” –

9.   National Library of Medicine: “Hippocampal volume in women victimised by childhood sexual abuse” –

10.   American Psychiatric Association: “Expert Q&A: Dissociative Disorders” –

11.   The Sydney Morning Herald: “Woman to use multiple personalities in evidence against abusive father” –

12.   BBC News: “Dissociative Identity Disorder: The woman who created 2,500 personalities to survive” –

13.   American Psychiatric Association: “Patient Story: Dissociative Disorders” –


By Samara Macrae

Samara MacRae is a student at Brighton College, England. She hopes to pursue medicine in the future, and is especially interested in surgery and emergency medicine.

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