MPD, or Multiple Personality Disorder, is a mental health condition now more commonly referred to as Dissociative Identity Disorder (DID). It is characterized by the presence of two or more distinct personality states or identities within a single individual. These identities may have their own names, ages, histories, and characteristics, and they can take control of the person's behavior at different times. Individuals with MPD often experience gaps in memory and may not recall events that occurred while another identity was in control. This disorder is typically associated with severe trauma during early childhood, such as abuse or neglect. Treatment often involves psychotherapy to integrate the separate identities and address the underlying trauma.