Dissociative identity disorder (DID) is a mental illness that involves the sufferer experiencing at least two clear identities or personality states, also called alters, each of which has a fairly consistent way of viewing and relating to the world. Some individuals with DID have been found to have personality states that have distinctly different ways of reacting, in terms of emotions, pulse, blood pressure, and blood flow to the brain. This disorder was formerly called multiple personality disorder (MPD) and is often colloquially referred to as split personality disorder. Statistics regarding this disorder indicate that the incidence of DID is about 3% of patients in psychiatric hospitals and is described as occurring in females nine times more often than in males. However, this female preponderance may be due to difficulty identifying the disorder in males. Also, disagreement among mental health professionals about how this illness appears clinically, and if DID even exists, adds to the difficulty of estimating how often it occurs.
Some professionals continue to be of the opinion that DID does not exist. The nature of this skepticism is sometimes due to questions about why many more individuals who have endured the stress of terrible abuse as young children do not develop the disorder, why more children are not diagnosed as having DID, and why some DID sufferers have no history of tremendous trauma. One explanation for what some believe to be these inconsistencies is that given the highly complex and unknown nature of the human brain and psyche, many of those whom one would expect to develop dissociative identity disorder are spared due to their resilience. Another concern about the diagnosis of DID involves having to rely on the traumatic memories of those who suffer from this disorder. That DID is significantly more often assessed in individuals in North America compared to the rest of the world, for the most part, leads some practitioners to believe that DID is a culture-based myth rather than a true disorder. As with many other mental health issues, symptoms of the same disorder in children look very different than symptoms in adults. Studies that verify the presence of DID using multiple resources add credibility to the diagnosis. Research on individuals with DID that have little to no media exposure to information on the illness lends further credibility to the reliability of the existence of this mental health condition.
Although there was a case study of DID as early as 1906, movies about DID first became well known in the United States since the 1950s. The 1953 movie The Three Faces of Eve tells the story of Chris Sizemore, a real-life woman with the disorder. She was thought to develop DID in reaction to witnessing several terrible accidents at a young age. That movie described three personalities that were successfully merged or integrated into one within one year. More accurately, the person depicted in that movie reportedly had to contend with 22 personalities that took more than 45 years to be able to coexist in a functional way. A television miniseries about DID was Sybil. The character of Sybil Dorsett portrayed the life story of Shirley Ardell Mason, who experienced severe physical, emotional, and sexual abuse that was inflicted by her mother. She was thought to develop 16 distinct identities. As with the diagnosis in general, the veracity of the story of Sybil remains a controversy, with claims that the illness in general, and Sybil specifically, is a hoax.
