New TV Series Explores the Debate Over a Multiple Personality Diagnosis
“Sybil,” about a woman who claimed to have 16 distinct personalities, sold over 6 million copies.

A series of rapes near the Ohio State campus in Columbus in the late 1970s terrorized the community. A suspect, Billy Milligan, was soon arrested and accused of the crimes. Now a new Netflix docuseries, “Monsters Inside: The 24 Faces of Billy Milligan,” examines his background, the charges against him, and the strategy that lawyers relied on for his defense.
In psychiatric evaluations after Milligan's arrest, doctors uncovered what they claimed was evidence of distinct personalities, each unaware of the others. The diagnosis: multiple personality disorder, a syndrome now known as dissociative identity disorder. Sexual and physical abuse during childhood were to blame, doctors said, for causing Milligan's personality to fracture as a form of self-protection.
The Milligan case, and the diagnosis, drew heavy attention from the news media at the time. “The man with 10 personalities: Which is guilty of his crimes?” read one headline. As his trial began in December 1978, an article published in The Austin American-Statesman proclaimed: “Once thought extremely rare, the multiple personality syndrome is now being recognized as widespread, at least by therapists who treat it.”
The disorder was already familiar to many Americans. A few years earlier, in 1973, a book titled “Sybil,” about a woman who claimed to have 16 distinct personalities, sold over 6 million copies. A television movie starring Sally Field followed in 1976, bringing the woman (whose real name was Shirley Mason) and the disorder into the public eye. Interviews with the book's co-authors, Mason's psychiatrist, Dr. Cornelia Wilbur, and the journalist Flora Rheta Schreiber, appeared on talk shows and in print, and their profiles rose quickly.
So too did recognition of the disorder. Until “Sybil” was published, only about 100 cases had ever been reported in medical literature. But before long, M.P.D. cases began to climb. Less than a decade later, the American Psychiatric Association officially recognized the diagnosis.
Retro Report explores the story of “Sybil” in a 2014 documentary “Is Multiple Personality Disorder Real? One Woman’s Story.” Questions about the disorder and its prevalence soon began to emerge, and the Retro Report film traces mounting doubts about Dr. Wilbur, her methods and the M.P.D. diagnosis.
One part of the debate centered on whether probing psychiatrists could influence susceptible patients, resulting in incorrect diagnoses of M.P.D. The notion of recovered memories came under scrutiny amid lawsuits by psychiatric patients who realized that they had recalled childhood abuse that may never have happened.
In 1994, Multiple Personality Disorder was officially renamed Dissociative Identity Disorder. “The M.P.D. thing had gotten to be such a lightning rod in the field,” Richard McNally, a psychology professor at Harvard, told Retro Report, “It probably was better to give it a little more boring name.”
Dr. David Spiegel at Stanford, who led the medical committee that changed the name, said the phrase “multiple personalities” could be misleading. “Multiple personality carries with it the implication that they really have more than one personality,” Dr. David Spiegel told Retro Report. “Dissociative Identity Disorder implies that the problem is fragmentation of identity – not that you really are 12 people; that you have not more than one, but less than one personality.”
“Monsters Inside,” takes viewers back to the days of M.P.D., just in time for the 45th anniversary of the 1976 TV movie “Sybil.” Milligan’s legal team succeeded in building his defense around the M.P.D. diagnosis, and he was found not guilty by reason of insanity. One of the doctors behind the diagnosis? None other than Dr. Cornelia Wilbur.
SARAH WEISER is a producer at Retro Report. This article first appeared in Retro Report’s free weekly newsletter. Subscribe and receive lessons from history in your mailbox. Follow us on Twitter @RetroReport.
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