Maybe Sybil just needed a good night's sleep.
Multiple personality disorder is a rare and extreme form of what psychiatrists call "dissociative disorder," and it was popularized by the publication in the early 1970s of the novel "Sybil." Psychiatrists have long thought that dissociative disorder might be a person's natural response to extreme trauma, such as child sexual abuse, during which a victim might psychologically protect him or herself by "going away." A patient experiencing dissociation might describe feeling outside or separate from himself or from reality. Taking on an alter personality--or several--was thought to be a variant of that psychological strategy of self-protection.
But a new article on the subject suggests that multiple personalities and other forms of dissociation may not be a direct response to trauma but the result of an unholy trinity: sleep problems (which in some cases may follow trauma), a patient who is highly suggestible to begin with, and a psychotherapist plumbing for blocked memories. The article is set for publication in the journal Current Directions in Psychological Science.
We already know that there's an element of suggestibility to multiple-personality disorder. In the wake of Sybil's publication and the release of a movie by the same name, instances of multiple personality disorder shot up, and continue to spike after entertainment or media accounts of the disorder appear. Like the young women in Leroy, N.Y., who have recently reported an outbreak of Tourette syndrome-like symptoms, psychological contagion appears to play a role in the spread of dissociative disorder.