Dissociative Identity Disorder (DID) is a psychiatric diagnosis where a person displays multiple distinct identities or personalities, each with their own memories and patterns of behavior. DID is caused by severe childhood trauma like abuse and neglect. The child dissociates or splits their identity as a coping mechanism. Symptoms include memory loss, depression, hallucinations, and an inability to account for certain events. Treatment focuses on psychotherapy to help integrate the different personalities. DID is difficult to treat and prognosis depends on comorbid conditions and ability to remove oneself from abusive situations.