Multiple Personality Disorder, now known as Dissociative Identity Disorder (DID), is a mental health condition where a person has two or more distinct identities or personality states. Each identity may have its own name, age, history, and characteristics. This disorder often develops as a response to severe trauma, such as abuse, during childhood, allowing the individual to cope by creating separate identities. People with DID may experience gaps in memory and may not recall events that occurred while another identity was in control. Treatment typically involves therapy, where individuals work to integrate their identities and address the underlying trauma, helping them lead a more cohesive life.