Home > Encyclopedia of Mental Disorders > Dissociative identity disorder

Definition

Previously known as multiple personality disorder, dissociative identity disorder (DID) is a condition in which a person has more than one distinct identity or personality state. At least two of these personalities repeatedly assert themselves to control the affected person's behavior. Each personality state has a distinct name, past, identity, and self-image.

Psychiatrists and psychologists use a handbook called the Diagnostic and Statistical Manual of Mental Disorders , fourth edition text revision or DSM-IV-TR, to diagnose mental disorders. In this handbook, DID is classified as a dissociative disorder. Other mental disorders in this category include depersonalization disorder,