What disease did Sybil, the world's most famous multiple-personality patient, actually have?

Sybil, the book supposedly based on a real case study, made the concept of multiple personality disorder world-famous, and launched a pop culture phenomenon. The only trouble is, it's based on a woman who didn't actually have multiple personalities. What diagnosis did she actually have? »6/11/12 2:19pm6/11/12 2:19pm