Multiple Personality Disorder (MPD) or Dissociative Identity Disorder (DID) was first recognized in the 1700's but was not understood so therefore it was forgotten. Many cases show up in medical records through the years, but in 1905, Dr. Morton Prince wrote a book about MPD that is a foundation for the disorder. A few years after it was published Sigmund Freud dismissed the disorder and this dropped it from being discussed at any credible mental health meetings. .
Since then the disorder has been overlooked and misdiagnosed as either schizophrenia or psychosis. Many in the medical profession did not believe that a person could unknowingly have more than one personality or person inside one body, even after the in the 1950's Three Faces of Eve was published by two psychiatrist. In 1993, records showed that three to five thousand patients were being treated for MPD compared to the hundred cases reported ten years earlier. There is still as increase in the number of cases being reported as the scientific community learns more and more about the disease and the public is becoming more and more aware of this mental disorder. .
There are still many questions left unanswered about the disease, like "Is it genetic?" or "Is a certain type of personality more vulnerable to the disorder?" but many aspects of how people come by the disorder are already answered (Clark, 1993, p.17-19) MPD is commonly found in adults who were recurrently abused mentally, physically, emotionally, and/or sexually as young children, between birth to 8 years of age. The child .
uses a process called dissociation to remove him/herself from the abusive situation. Dissociation is when a child makes up an imaginary personality to take control of the mind and body while the child is being abused. The child can imagine many personalities but usually there is a personality for every feeling and or emotion that was involved during the abuse (BoyyM, 1998, p.