The correct answer is dissociative identity disorder
The disorder can be defined as a severe psychological condition in which important aspects such as memories, behaviors, feelings and the identity itself are affected. It is configured as a dissociative mental process responsible for the lack of connection to what the person brings in his 'real' personality.
Dissociative Identity Disorder is caused by a major trauma suffered by the person even in childhood. In many cases, these traumatic events are the result of sexual, physical or psychological abuse. By going through these situations, children begin to develop other personalities in order to defend themselves from this harmful exposure. These characters act as objects of self-defense to endure moments of pain and anguish.