In the DSM of 1987, the diagnostic feature of multiple personality disorder known as inter-personality amnesia was removed. This was an error that was later corrected in the fourth edition of the DSM. Without amnesia being a criteria that is needed for diagnosis it was difficult to differentiate between the different types of dissociative disorders. With amnesia reinstated as a criterion, there can still be difficulty with discriminating between the dissociative, bipolar, and borderline personality disorder as well as sometimes schizophrenia. This difficulties in really being able to differentiate between disorders is believed to lend a hand in many cases of