Debbie Nathan, author: "Sybil Exposed: The Extraordinary Story Behind The Famous Multiple Personality Case" (Free Press, 2011), New York, N.Y.
Paul McHugh, University distinguished service professor of psychiatry, Johns Hopkins University, Baltimore, Md.
Bethany Brand, professor of psychology, Towson University, Towson, Md.
In a new book writer Debbie Nathan digs into archived material documenting the experiences of a patient known as "Sybil," who reportedly suffered from multiple personality disorder. Ira Flatow and guests discuss MPD, and its modern equivalent—dissociative identity disorder.