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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