Dissociative identity disorder

Dissociative identity disorder (DID), previously known as multiple personality disorder (MPD), is characterized by the presence of at least two personality states or "alters". The diagnosis is extremely controversial, largely due to disagreement over how the disorder develops.^[5][6][7] Proponents of DID support the trauma model, viewing the disorder as an organic response to severe childhood trauma. Critics of the trauma model support the sociogenic (fantasy) model of DID as a societal construct and learned behavior used to express underlying distress, developed through iatrogenesis in therapy, cultural beliefs about the disorder, and exposure to the concept in media or online forums. The disorder was popularized in purportedly true books and films in the 20th century; Sybil became the basis for many elements of the diagnosis, but was later found to be fraudulent.^[5]

The disorder is accompanied by memory gaps more severe than could be explained by ordinary forgetfulness.^[1][8] These are total memory gaps, meaning they include gaps in consciousness, basic bodily functions, perception, and all behaviors.^[1] Some clinicians view it as a form of hysteria.^[5] After a sharp decline in publications in the early 2000s from the initial peak in the 90s, Pope et al. described the disorder as an academic fad.^[9] Boysen et al. described research as steady.^[10]

According to the DSM-5-TR, early childhood trauma, typically starting before 5–6 years of age, places someone at risk of developing dissociative identity disorder.^{[11](p334)[12]} Across diverse geographic regions, 90% of people diagnosed with dissociative identity disorder report experiencing multiple forms of childhood abuse, such as rape, violence, neglect, or severe bullying.^[11](p334) Other traumatic childhood experiences that have been reported include painful medical and surgical procedures,^{[11](p334)[13]} war,^[11](p334) terrorism,^[11](p334) attachment disturbance,^[11](p334) natural disaster, cult and occult abuse, loss of a loved one or loved ones,^[13] human trafficking,^[11](p334) and dysfunctional family dynamics.^{[11](p334)[14]}

There is no medication to treat DID directly, but medications can be used for comorbid disorders or targeted symptom relief—for example, antidepressants for anxiety and depression or sedative-hypnotics to improve sleep.^[15][16] Treatment generally involves supportive care and psychotherapy.^[3] The condition generally does not remit without treatment, and many patients have a lifelong course.^[3][17]

Lifetime prevalence was found to be 1.1–1.5% of the general population (based on multiple epidemiological studies) and 3.9% of those admitted to psychiatric hospitals in Europe and North America.^{[1][11](p334)[15]} DID is diagnosed 6–9 times more often in women than in men.^[8]

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, but it is unclear whether increased rates of diagnosis are due to better recognition or to sociocultural factors such as mass media portrayals.^[8] The typical presenting symptoms in different regions of the world may also vary depending on culture, such as alter identities taking the form of possessing spirits, deities, ghosts, or mythical creatures in cultures where possession states are normative.^{[1][11](p335)}