Looking back at the long and storied history of literature, film, and other narrative art forms, one trend becomes abundantly clear: writers love mental illness. From depression to bipolar disorder to schizophrenia, psychiatric disorders have been used by artists for hundreds of years to heighten drama, make heroes more heroic, villains more villainous, and allow actors to flex their acting chops – sometimes with unfortunate real-world implications. But few disorders have captured the imagination of writers and audiences like Dissociative Identity Disorder or DID – better known as Multiple Personality Disorder. Characterized by the expression of multiple distinct personality types by a single person – often accompanied by amnesia of each expression – DID has been featured in dozens of books and films from 1957’s The Three Faces of Eve and 1973’s Sybil to 1999’s Fight Club, 2009’s United States of Tara, and 2016’s Split. Given the disorder’s ubiquity in popular media, one could be forgiven for thinking that DID is a relatively common affliction, or at least one well-documented in the psychiatric literature. In reality, however, DID remains a poorly-defined, poorly understood, and highly controversial diagnosis, with many psychiatrists questioning whether the disorder even exists at all.

Accounts of people switching between multiple personalities have existed since the dawn of human history, with the phenomenon often being attributed to possession by spirits, demons, muses, and other mystical entities. However, the first medical descriptions of what we would now recognize as Dissociative Identity Disorder would not appear until the late 19th Century, the most famous being the curious case of Louis Vivet. Born in 1863 in Paris, Vivet had a miserable childhood, being frequently beaten and starved by his mother. At age eight Vivet ran away from home to become a vagrant and a  thief, spending most of his childhood in and out of correctional institutions. At age 17, while Vivet was working as a labourer on a vineyard, a venomous snake wound itself around his arm, triggering a hysterical episode and a series of violent convulsions which resulted in him becoming paralyzed below the waist. In 1880, Vivet was transferred to an asylum and trained to become a tailor to support himself. During his stay he continued to suffer frequent epileptic seizures, until around a year later when he suddenly regained the use of his legs. While this in itself was highly unusual, more unusual still was the fact that this miraculous recovery was accompanied by a complete change of personality. While paralyzed, Vivet had been a calm, hardworking, pleasant individual; suddenly, however, he became rude, quarrelsome, and utterly lacking in morals. Stranger still, he no longer seemed to recognize his fellow patients or attending doctors, as though he had become a completely different person altogether. This constant switching back and forth between two distinct personalities would persist for the rest of Vivet’s life, which was spent in and out of asylums being evaluated by increasingly-curious doctors. In 1882, a Doctor Camuset at the psychiatric hospital in Bonneval diagnosed Vivet’s condition as redoublement [“Ruh-doo-bluh-mahn”] or “doubling,” a term recently introduced by French surgeon Étienne Azam in reference to a patient he named “Félida X.” Like Vivet, Félida frequently switched between two distinct personality states – one serious and reserved and one cheerful and easygoing – neither of which appeared aware of the other. The cases of Louis Vivet and Félida X fascinated the medical community and public alike, and are believed to have partially inspired Robert Louis Stevenson’s classic 1886 novella The Strange Case of Dr. Jekyll and Mr. Hyde.  (As a brief aside here, you might think the “Jekyll” in “The Strange Case of Dr. Jekyll and Mr. Hyde” is pronounced such that it rhymes with “freckle,” but you’d be wrong.  According to Stevenson, the name should be pronounced “Jee-kal” as in rhymes with “fecal”.)

In any event, over the next twenty years, dozens more cases of redoublement would appear in the medical literature, with the phenomenon eventually acquiring a new name: Multiple Personality Disorder, or MPD. French neurologist Jean-Martin Charcot [“Zhahn Mart-tayn Shar-coh”] classified MPD as a dissociative disorder – linking it with so-called fugue states in which patients black out and wander about completely unaware of their surroundings – while Sigmund Freud made the causal link between MPD and childhood trauma.Yet no sooner had Multiple Personality Disorder appeared in the medical lexicon did it immediately fall out of fashion. In 1908, Swiss psychiatrist Eugen Bleuler coined the term schizophrenia to describe a wide spectrum of psychotic and delusional disorders previously referred to as dementia praecox. Schizophrenia in Greek literally means “split brain,” and was intended by Bleuler to convey the process of the mind splitting off from reality. As Bleuler believed the development of multiple personalities to be the result such a split, he classified MPD under the wider schizophrenia umbrella. Unfortunately, this misleading terminology resulted in a popular confusion between DID and schizophrenia that persists to this day. A second major factor in the early abandonment of MPD as a diagnostic category was the revelation that many of Charcot’s alleged MDP patients were in fact frauds putting on an act for attention. Due to these and other factors, diagnoses of MPD all but disappeared from the medical literature for nearly half a century.

Then, in 1957, American psychiatrists Corbett H. Thigpen and Hervey M. Cleckly published The Three Faces of Eve, a non-fiction account of patient Christine Sizemore – referred to in the book as “Eve White” to protect her identity.  Born Christine Costner in 1927 in Edgefield, South Carolina, Sizemore began dissociating at the age of two in response to a series of traumatic incidents, including seeing a man cut in half at the local lumber mill and being physically and sexually abused by her parents. She suffered from large gaps in her memory, finding herself being punished for acts of disobedience she did not remember committing and baffled by school tests she did not remember studying for. Later in life she would often wake up with unexplained hangovers and an unsavoury reputation at local bars. Eventually it emerged that Sizemore’s psyche had fractured into three distinct personalities – the shy, depressed “Eve White”; extroverted, mischievous party girl “Eve Black”; and pleasant, sensible “Jane” – the transition between the three often being signalled by a splitting headache. This fracture was only exacerbated by her first marriage to an abusive man, leading to an incident in which she nearly strangled her young daughter with the cord from a Venetian blind.

In 1951, Sizemore began undergoing therapy with Corbett Thigpen, who noted even more bizarre aspects of her disorder such as the fact that her different personalities possessed entirely different skillsets. For example, some of Sizemore’s personalities knew how to drive while others did not, while at one point Sizemore opened a tailoring shop in Manassas, Virginia because one of her personalities was a skilled seamstress. The three personalities spoke and dressed differently and even had different appetites, with Sizemore at one point gaining a large amount of weight as she attempted to feed three different people within the same body.  But the amnesia so typical of MPD seemed to be strangely asymmetric; while “Eve White” remained unaware of the behaviour and thoughts of her two alters, “Eve Black” knew everything about her host personality and delighted in torturing her. And as the therapy sessions progressed, this internal arrangement began to collapse and shift, with “Eve White” and “Eve Black” eventually disappearing only to be replaced by a rotating cast of new alters, nearly always in groups of three. However, according to The Three Faces of Eve Thigpen eventually managed to dissolve and merge these personalities, and Christine went on to marry electrician Don Sizemore and live a long and happy life, dying in 2016 at the age of 89.

The Three Faces of Eve became an instant bestseller, and in 1957 was adapted into a film of the same name starring Joanne Woodward, who won the Academy Award for Best Actress for her portrayal of Christine Sizemore. But while the book and film did much to revive public awareness of MPD, its impact was dwarfed two decades later by the 1973 book Sybil. Written by journalist Flora Rheta Schrieber, Sybil tells the story of art teacher Sybil Dorsett – real name Shirley Ardell Mason – whose case of Multiple Personality Disorder was even more extreme than Christine Sizemore’s. Born in 1923 in Dodge Center, Minnesota, Mason was heavily abused by her mother, Martha Atkinson, whom Schrieber speculates may have suffered from schizophrenia. According to Sybil, Martha tortured her daughter in particularly sadistic ways, such as sexually violating her with a buttonhook or tying her to a piano and forbidding her from urinating while she played. This trauma resulted in Mason’s psyche fracturing into no fewer than sixteen distinct personalities, including a baby named Ruthie, a writer and painter named Marcia, a French-speaking girl named Vicky, two male handymen named Mike and Sid, a skilled pianist named Vanessa, a strict religious conservative named Clara, and a listless, nearly paralyzed woman named Sybil. In 1954, Mason began seeking treatment from psychiatrist Cornelia B. Wilbur, the two continuing to work together for 11 years. As in the case of Christine Sizemore, Wilbur eventually succeeded in bringing out a stable, confident personality named simply “The Blonde” and merging all the other personalities into her, effectively curing Mason and allowing her to live a happy, normal life.

Like The Three Faces of Eve, Sybil became an immediate bestseller and was adapted into a 1976 TV movie starring Sally Field in the title role and Joanne Woodward from The Three Faces of Eve as Doctor Wilbur. In the wake of the film, which won four Emmy Awards, “Sybil Dorsett” became one of the most famous psychiatric patients in history and popular interest in Multiple Personality Disorder exploded. While MPD had previously been one of the rarest psychiatric diagnoses, with only 26 recorded cases prior to 1976, between 1985 and 1995 more than 40,000 people were diagnosed with the disorder. MPD sufferers began appearing on the talk show circuit, some exhibiting as many as 4,500 distinct personalities. In certain cases these alters extended beyond the human, with certain individuals presenting as ducks, chickens, lobsters, tigers, gorillas, unicorns, and even angels or God.

Meanwhile, the psychiatric field scrambled to keep up with the explosion in MPD diagnoses. At the time, the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Second Edition, or DSM-II, only briefly mentioned the disorder as a subtype of “hysterical neurosis.” But in 1980, thanks to a concerted lobbying effort by therapists, MPD was listed in the DSM-III as its own distinct syndrome, which the DSM-IV later renamed Dissociative Identity Disorder. In 1984 the International Society for the Study of Multiple Personality and Dissociation was founded in Chicago, while in 1988 the dedicated medical journal Dissociation began publication. By 1990 the number of papers published on DID had increased by 6,000 percent since the 1970s.

According to the American Psychiatric Association website, Dissociative Identity Disorder is currently defined by:

• The existence of two or more distinct identities (or “personality states”). The distinct identities are accompanied by changes in behaviour, memory and thinking. The signs and symptoms may be observed by others or reported by the individual.
• Ongoing gaps in memory about everyday events, personal information and/or past traumatic events.
• The symptoms cause significant distress or problems in social, occupational or other areas of functioning.

 As the name suggests, DID is classified among the dissociative disorders, syndromes characterized by normally integrated psychological processes becoming detached from each other and from reality. The other dissociative disorders include dissociative amnesia, in which a person suddenly experiences large gaps in their memory not explainable by normal forgetfulness or other memory disorders; dissociative fugue, in which a person loses awareness of their surroundings and unexpectedly wanders off; depersonalization disorder, in which a person feels detached from their bodies or surroundings, and dissociative identity disorder not otherwise specified, or DID-NOS, a catchall term for dissociative disorders which do not fall into any other category. All dissociative disorders a typically associated with some kind of traumatic trigger – such as childhood physical or sexual abuse in the case of DID. Thus, DID is widely considered to be a kind of defence mechanism, allowing the sufferer to compartmentalize traumatic memories within one or more personalities who are unaware of each other. As Cornelia Wilbur explains in Sybil:

“If you are too scared to face something, then it just makes perfectly good sense to black out. Then you’ll never have to know what you’re scared of.”

But not all may be what it seems. Despite DID’s official recognition by the American Psychiatric Association, the disorder and its diagnosis have long been mired in controversy. Early on in the DID boom of the 80’s and 90s, many psychiatrists noticed that the vast majority of purported sufferers presented almost identically to the most well-publicized DID case – that presented in Sybil – with almost none presenting with the milder symptoms of Christine Sizemore or Louis Vivet. Indeed, the average MPD sufferer was found to be very similar demographically to Shirley Mason – white, female, and around 30 years of age. This has led many to speculate that the extraordinary rise in DID diagnoses following the 1970s was a case of social contagion, with patients modelling their behaviour – intentionally or not – after poplar depictions of the disorder in works like The Three Faces of Eve, Sybil, and talk shows like The Oprah Winfrey Show and Jerry Springer. This is similar to how nearly all accounts of UFOs and alien abductions began following a broadly similar pattern after the release of popular alien-themed works like Close Encounters of the Third Kind and Communion in the 1970s and 80s. This explanation is especially plausible given the typically extreme manifestation of the disorder in the most high-profile DID patients. If such dramatic presentations of DID were anywhere near as common as the talk shows claimed, the disorder would be easier to diagnose and far more than 26 cases would have been described prior to the 1970s.

But while the media has played a major role in exaggerating the prevalence of DID, the psychiatric field is equally guilty of muddying the waters. In the 1960s, psychiatrist Herbert Spiegel was asked by Cornelia Wilbur to help refine her diagnosis of Shirley Mason, AKA “Sybil.” In the course of his evaluation, Spiegel discovered to his shock that many of Mason’s alternate personalities had only emerged as a result of Wilbur’s suggestions during therapy. Indeed, Spiegel found Mason to be highly suggestible, while Wilbur’s methods incorporated many techniques commonly used in hypnosis. Much of Mason’s disorder was thus invented during her therapy sessions, with Wilbur and Flora Schrieber, the author of Sybil, even admitting to Spiegel that Mason had to be diagnosed with MPD otherwise their book on the case couldn’t be published. Later investigators uncovered a similar pattern in the case of Christine Sizemore, discovering, for example, that her third personality, “Jane,” only emerged during her therapy sessions with Corbett Thigpen. In his 2012 book The Rape of Eve, psychiatrist Colin Ross describes Thigpen as unethical and exploitative, manipulating Sizemore’s disorder for personal gain:

“At different times he functioned as her psychotherapist, publicist, literary agent, film agent, book editor, contracts negotiator and legal adviser. He attended her husband’s funeral uninvited, was her son’s godfather and engaged in sexual misconduct with her. He arranged for her to have an abortion, and during the procedure she was sterilized without her or her husband’s consent.”

Furthermore, contrary to the narrative described in The Three Faces of Eve, Thigpen did not actually succeed in curing Sizemore of her DID. In fact she continued to dissociate, straining her marriage to the breaking point, for another two decades. It was not until 1974 that psychiatrist Tony Tsitos managed to merge her personalities and allow her to live a normal life.

These revelations in turn led to a major reevaluation of many DID cases, and a disturbing pattern emerged. The boom in DID diagnoses coincided with another major trend in the field of psychiatry: that of recovering repressed childhood memories. Ever since Freud, many psychiatrists have believed that people’s minds are capable of repressing traumatic memories such as childhood sexual abuse, and that through psychoanalysis, hypnosis, and other techniques, these memories can be recovered. This concept gained considerable public attention in the 1980s and 90s when expert testimony from psychiatrists claiming to have recovered their patient’s repressed memories was used to achieve convictions in several high-profile sexual abuse trials. Unfortunately, it was soon discovered that the whole notion of repressed memories is, in fact, a fallacy, and that patients’ supposed recollections of childhood abuse were generally false memories inadvertently planted by their psychiatrists through suggestion. (See our video: Do Repressed Memories Actually Exist for many more details.)

In any event, as DID is classically associated with childhood sexual abuse and other trauma, the clinical triggers of many purported DID sufferers were likewise found to be merely implanted suggestions. The debunking of repressed memories ignited a major scandal within the psychiatric community, with Harvard psychologist Dr. Richard McNally writing:

“The notion that traumatic events can be repressed and later recovered is the most pernicious bit of folklore ever to infect psychology and psychiatry. It has provided the theoretical basis for ‘recovered memory therapy’ — the worst catastrophe to befall the mental health field since the lobotomy era.”

Thus, while DID remains a recognized disorder in the DSM-V, nowadays psychiatrists are much more hesitant and selective in diagnosing it, recognizing that many of the symptoms of DID overlap with other, more common disorders including schizophrenia, ADHD, epilepsy, and conversion disorders; and that the presentation of the disorder is very culturally specific, with many cultures who believe in spirit possession not considering the disorder to be pathological. Based on more recent diagnostic criteria, researchers estimate that DID affects no more than 1.5% of the general population. However, in a 1995 review of DID cases at the Johns Hopkins University School of Medicine, psychiatrist Paul McHugh concluded that nearly all cases showed the “hand of the artisan,” meaning that at least some aspects of the disorder’s presentation is directly influenced by the attending psychiatrist.

The legitimacy of DID as a psychiatric diagnosis has dire real-life consequences, especially in the field of criminal law. In 1977, 22-year-old Billy Milligan was arrested and charged with the rape of three women on the Ohio State University campus. While awaiting trial, Milligan was diagnosed with Dissociative Identity Disorder by psychologist Dorothy Turner. During the trial itself, Turner and Milligan’s lawyers testified that one of Milligan’s 10 alternate personalities had been in control during the rapes, and that Milligan himself had no memory of his actions. Based on this testimony, the Judge accepted a plea of not guilty by reason of insanity and Milligan spent 10 years in psychiatric institutions, being released from the Ohio mental health system in 1988. This and other similar cases raised concerns among legal experts that false claims of DID could potentially be used by criminals to deny responsibility and avoid jail time. However, in recent years American courts have generally rejected the admissibility of DID diagnoses as evidence, on the grounds that the scientific evidence fails to meet legal reliability standards and is therefore not useful to either the judge or jury.

Meanwhile, a small but dedicated group of people known as the Multiplicity Community is not only convinced that DID is absolutely a real phenomenon, but is fighting to have it recognized not as a disorder to be cured, but rather an alternate but ultimately healthy state of being. Within this community, bodies containing multiple individuals or personalities are known as a “multiplicity systems”, while those with only one personality are referred to as “singlets.”As presenting all the members of the system in public could potentially cause problems, most multiplicity systems engage in the practice of “fronting,” only presenting a single personality to the world as a singlet would. As the multiplicity system Falah Liang explains:

“We are not openly multiple. All of us disguise our behaviour under one mask, one public persona, in essence appearing non-multiple to the outside eye and to most people we interact with. We’re able to share memories and communicate among ourselves internally, so it’s easy for us. We wear the mask well and look like your standard non-multiple [person], but it can be tiring to wear the mask.”

Many in the Multiplicity Community are wary of the diagnostic label of DID, arguing that it unfairly and unnecessarily pathologizes their state of being, which they view as simply another type of neurodivergence akin to being left-handed or on the autism spectrum. They also dispute the terms “identity” and “personality”, arguing that these imply that members of a multiplicity system are not real, full-fledged individuals but merely fragments of a larger, truer “self” that must be unified through psychotherapy. As multiplicity system Anthony Temple explains:

“Any time that a multiple group lives in fear of the consequences of coming out of the closet, they are being denied their social rights. There should not be one model of reality imposed upon everyone. Society can and should change to accept those who are different, rather than enforcing a single standard of normality and punishing those who don’t fit.”

Meanwhile, many psychiatrists consider the multiplicity community’s claim that DID is a perfectly healthy form of neurodivergence to be counter-productive, discouraging many sufferers from seeking the psychiatric help they desperately need. Thus, between this debate and the aforementioned speculation that most DID sufferers are either frauds, misdiagnosed, or simply being unintentionally manipulated by their psychiatrists, the jury remains very much out on how Dissociative Identity Disorder should be defined or whether it even exists at all.

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