Vivet was the subject of countless medical papers and became the most studied case of dissociation in the 19th century. Between 1880 and 1920, various international medical conferences devoted time to sessions on dissociation. It was in this climate that Jean-Martin Charcot introduced his ideas of the impact of nervous shocks as a cause for a variety of neurological conditions. One of Charcots students, Pierre Janet, took these ideas and went on to develop his own theories of dissociation. One of the first individuals diagnosed with multiple personalities to be scientifically studied was Clara Norton Fowler, under the pseudonym Christine Beauchamp; American neurologist Morton Prince studied Fowler between 1898 and 1904, describing her case study in his 1906 monograph, Dissociation of a Personality. 20th century
In the early 20th century, interest in dissociation and multiple personalities waned for several reasons. After Charcots death in 1893, many of his so-called hysterical patients were exposed as frauds, and Janets association with Charcot tarnished his theories of dissociation. Sigmund Freud recanted his earlier emphasis on dissociation and childhood trauma.In 1908, Eugen Bleuler introduced the term "schizophrenia" to represent a revised disease concept for Emil Kraepelins dementia praecox. Whereas Kraepelins natural disease entity was anchored in the metaphor of progressive deterioration and mental weakness and defect, Bleuler offered a reinterpretation based on dissociation or "splitting" (Spaltung) and widely broadened the inclusion criteria for the diagnosis.
Book and film Sybil
In 1974, the highly influential book Sybil was published, and later made into a miniseries in 1976 and again in 2007. Describing what Robert Rieber called "the third most famous of multiple personality cases," it presented a detailed discussion of the problems of treatment of "Sybil Isabel Dorsett", a pseudonym for Shirley Ardell Mason. Though the book and subsequent films helped popularize the diagnosis and trigger an epidemic of the diagnosis, later analysis of the case suggested different interpretations, ranging from Masons problems having been caused by the therapeutic methods used by her psychiatrist, C.B. Wilbur, or an inadvertent hoax due in part to the lucrative publishing rights, though this conclusion has itself been challenged.David Spiegel, a Stanford psychiatrist whose father treated Shirley Ardell Mason on occasion, says that his father described Mason as "a brilliant hysteric. He felt that Wilbur tended to pressure her to exaggerate on the dissociation she already had." As media attention on DID increased, so too did the controversy surrounding the diagnosis. Re-classifications
With the publication of the DSM-III, which omitted the terms "hysteria" and "neurosis" (and thus the former categories for dissociative disorders), dissociative diagnoses became "orphans" with their own categories with dissociative identity disorder appearing as "multiple personality disorder".In the opinion of McGill University psychiatrist Joel Paris, this inadvertently legitimized them by forcing textbooks, which mimicked the structure of the DSM, to include a separate chapter on them and resulted in an increase in diagnosis of dissociative conditions.