Multiple personality disorder. Abstract computer image depicting a young woman suffering from multiple personality disorder. Multiple images of her face are seen in a stacked row. Multiple personality disorder is also known as split" personality. It is a rare form of mental illness in which a person has two or more distinct personalities, each dominating at different times. The personalities are usually completely different and are often polar opposites as in the story of Dr Jekyll and Mr Hyde. This image may otherwise also depict schizophrenia, a state of paranoid and deluded thinking. It may also show a person in the process of hallucination."