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
DID is controversial within both the field of psychiatry and the legal system. Claims of DID have been used only rarely to argue criminal insanity in court.It is unclear whether increased rates of the disorder are due to better recognition or sociocultural factors such as mass media portrayals. The typical presenting symptoms in different regions of the world may also vary depending on culture, for example alter identities taking the form of possessing spirits, deities, ghosts, or mythical figures in cultures where normative possession states are common. (pp 295, 801) The possession form of dissociative identity disorder is involuntary and distressing, and occurs in a way that violates cultural or religious norms. (p 295)

Definitions
Dissociation, the term that underlies dissociative disorders including DID, lacks a precise, empirical, and generally agreed upon definition.A large number of diverse experiences have been termed dissociative, ranging from normal failures in attention to the breakdowns in memory processes characterized by the dissociative disorders.
Those with DID generally have adequate reality testing; they may have positive Schneiderian symptoms of schizophrenia but lack the negative symptoms. They perceive any voices heard as coming from inside their heads (patients with schizophrenia experience them as external). In addition, individuals with psychosis are much less susceptible to hypnosis than those with DID. Difficulties in differential diagnosis are increased in children.DID must be distinguished from, or determined if comorbid with, a variety of disorders including mood disorders, psychosis, anxiety disorders, PTSD, personality disorders, cognitive disorders, neurological disorders, epilepsy, somatoform disorder, factitious disorder, malingering, other dissociative disorders, and trance states. An additional aspect of the controversy of diagnosis is that there are many forms of dissociation and memory lapses, which can be common in both stressful and nonstressful situations and can be attributed to much less controversial diagnoses. Individuals faking or mimicking DID due to factitious disorder will typically exaggerate symptoms (particularly when observed), lie, blame bad behavior on symptoms and often show little distress regarding their apparent diagnosis. In contrast, genuine people with DID typically exhibit confusion, distress and shame regarding their symptoms and history.A relationship between DID and borderline personality disorder has been posited, with various clinicians noting overlap between symptoms and behaviors and it has been suggested that some cases of DID may arise "from a substrate of borderline traits".