Dissociative Identity Disorder (formerly known as multiple personality disorder) involves the person having two or more separate identities that can take control of the ‘host’ body. They may or may not know about each other. The development of Dissociative Identity Disorder has links with childhood sexual abuse and ritual abuse, though this may not be true for all. There will be disturbances in identity, loss of time and possibly knowledge of what they have been doing and may have other mental health issues alongside related to traumatic experiences.
For more information about DID, please see the following link: