<Tr> <Th> Frequency </Th> <Td> ~ 2% of people </Td> </Tr> <Tr> <Td_colspan="2"> (edit on Wikidata) </Td> </Tr> <P> Dissociative identity disorder (DID), also known as multiple personality disorder, is a mental disorder characterized by at least two distinct and relatively enduring personality states . There is often trouble remembering certain events, beyond what would be explained by ordinary forgetfulness . These states alternately show in a person's behavior . Presentations, however, are variable . Associated conditions often include borderline personality disorder, post traumatic stress disorder, depression, substance misuse disorder, self - harm, or anxiety . </P> <P> The cause is believed to be due to childhood trauma . In about 90% of cases there is a history of abuse in childhood, while other cases are linked to experiences of war or health problems during childhood . Genetic factors are also believed to play a role . An alternative hypothesis is that it is a by - product of techniques employed by some therapists, especially those using hypnosis . Before a diagnosis is made it should be verified that the person's condition is not better accounted for by substance abuse, seizures, imaginative play in children, or religious practices . </P>

What is it called when someone has split personalities