Etzel Cardena and David Gleaves believed the over-representation of DID in North America was the result of increased awareness and training about the condition which had formerly been missing. History
Early references
In the 19th century, "dédoublement", or "double consciousness", the historical precursor to DID, was frequently described as a state of sleepwalking, with scholars hypothesizing that the patients were switching between a normal consciousness and a "somnambulistic state".An intense interest in spiritualism, parapsychology and hypnosis continued throughout the 19th and early 20th centuries, running in parallel with John Lockes views that there was an association of ideas requiring the coexistence of feelings with awareness of the feelings. Hypnosis, which was pioneered in the late 18th century by Franz Mesmer and Armand-Marie Jacques de Chastenet, Marques de Puységur, challenged Lockes association of ideas. Hypnotists reported what they thought were second personalities emerging during hypnosis and wondered how two minds could coexist. In the 19th century, there were a number of reported cases of multiple personalities which Rieber estimated would be close to 100. Epilepsy was seen as a factor in some cases, and discussion of this connection continues into the present era.By the late 19th century, there was a general acceptance that emotionally traumatic experiences could cause long-term disorders which might display a variety of symptoms. These conversion disorders were found to occur in even the most resilient individuals, but with profound effect in someone with emotional instability like Louis Vivet (1863–? ), who had a traumatic experience as a 17-year-old when he encountered a viper.
Treatment and epidemiology
Treatment generally involves supportive care and psychotherapy. The condition usually persists without treatment. It is believed to affect about 1.5% of the general population (based on a small US community sample) and 3% of those admitted to hospitals with mental health issues in Europe and North America. DID is diagnosed about six times more often in women than in men. The number of recorded cases increased significantly in the latter half of the 20th century, along with the number of identities reported by those affected. Society and culture
DID is controversial within both the field of psychiatry and the legal system. Claims of DID have been used only rarely to argue criminal insanity in court.It is unclear whether increased rates of the disorder are due to better recognition or sociocultural factors such as mass media portrayals. The typical presenting symptoms in different regions of the world may also vary depending on culture, for example alter identities taking the form of possessing spirits, deities, ghosts, or mythical figures in cultures where normative possession states are common. (pp 295, 801) The possession form of dissociative identity disorder is involuntary and distressing, and occurs in a way that violates cultural or religious norms. (p 295)

Definitions
Dissociation, the term that underlies dissociative disorders including DID, lacks a precise, empirical, and generally agreed upon definition.A large number of diverse experiences have been termed dissociative, ranging from normal failures in attention to the breakdowns in memory processes characterized by the dissociative disorders.