Current expression replacing the now obsolete phrase “Multiple Personality Disorder.” When a person suffers from DID, he or she loses contact with their individual personality or ego state, and allows other egos to temporarily become the primary personality. The switch from one state to another is usually triggered by some external or internal stressor. Contrary to movies, novels, and poorly-trained people licensed in fields that are not explicity psychological in nature (such as nurses) or who do not have advanced studies in the subject, real Dissociative Identity Disorder is incredibly rare and only about 1% of dissociative disorders can be qualified as DID.