Dissociative identity disorder (DID), formerly known as multiple personality disorder or multiple personality syndrome, is a mental disorder characterized by the presence of at least two distinct and relatively enduring personality states. The disorder is accompanied by memory gaps more severe than could be explained by ordinary forgetfulness. The personality states alternately show in a person's behavior; however, presentations of the disorder vary. Other conditions that often occur in people with DID include post-traumatic stress disorder, personality disorders (especially borderline and avoidant), depression, substance use disorders, conversion disorder, somatic symptom disorder, eating disorders, obsessive–compulsive disorder, and sleep disorders. Self-harm, non-epileptic seizures, flashbacks with amnesia for content of flashbacks, anxiety disorders, and suicidality are also common. Overview The following three subsections give brief overviews of the proposed cause of dissociative identity disorder (DID) and how it is recognized; conventional treatment of DID, and how frequently it occurs; and finally how it is perceived in modern Western culture. All of the topics are treated in greater detail in later sections. Cause and diagnosis Dissociative identity disorder (DID) is the result of repeated or long-term childhood trauma, most frequently child abuse or neglect, that is combined with an insecure or disorganized attachment. DID cannot form after ages 6-9 because individuals older than these ages have an integrated self identity and history. Trauma later in life can lead to post-traumatic stress disorder or complex post-traumatic stress disorder, other dissociative disorders including other specified dissociative disorder, somatic symptom disorders, or possibly borderline personality disorder, but DID requires an unintegrated mind to form. Genetic and biological factors are also believed to play a role. The diagnosis should not be made if the person's condition is better accounted for by substance use disorder, seizures, other mental health problems, imaginative play in children, or religious practices. Treatment and epidemiology Treatment generally involves supportive care and psychotherapy. The condition usually persists without treatment. It is believed to affect about 1.5% of the general population (based on a small US community sample) and 3% of those admitted to hospitals with mental health issues in Europe and North America. DID is diagnosed about six times more often in women than in men. The number of recorded cases increased significantly in the latter half of the 20th century, along with the number of identities reported by those affected. Society and culture Claims of DID have been used only rarely to argue criminal