Others explain the increase as being due to the use of inappropriate therapeutic techniques in highly suggestible individuals, though this is itself controversial while proponents of DID claim the increase in incidence is due to increased recognition of and ability to recognize the disorder. Figures from psychiatric populations (inpatients and outpatients) show a wide diversity from different countries.A 1996 essay suggested three possible causes for the sudden increase of DID diagnoses, among which the author suspects the first being most likely:
The result of therapist suggestions to suggestible people, much as Charcots hysterics acted in accordance with his expectations. Psychiatrists past failure to recognize dissociation being redressed by new training and knowledge. Dissociative phenomena are actually increasing, but this increase only represents a new form of an old and protean entity: "hysteria".Dissociative disorders were excluded from the Epidemiological Catchment Area Project. North America
DID is considered a controversial diagnosis and condition, with much of the literature on DID still being generated and published in North America, to the extent that it was once regarded as a phenomenon confined to that continent though research has appeared discussing the appearance of DID in other countries and cultures. Although the condition has been described in non-English speaking nations and non-Western cultures, these reports all occur in English-language journals authored by international researchers who cite Western scientific literature and are therefore not isolated from Western influences.
Other arguments that therapy can cause DID, include the lack of children diagnosed with DID, the sudden spike in rates of diagnosis after 1980 (although DID was not a diagnosis until DSM-IV, published in 1994), the absence of evidence of increased rates of child abuse, the appearance of the disorder almost exclusively in individuals undergoing psychotherapy, particularly involving hypnosis, the presences of bizarre alternate identities (such as those claiming to be animals or mythological creatures) and an increase in the number of alternate identities over time (as well as an initial increase in their number as psychotherapy begins in DID-oriented therapy). These various cultural and therapeutic causes occur within a context of pre-existing psychopathology, notably borderline personality disorder, which is commonly comorbid with DID. In addition, presentations can vary across cultures, such as Indian patients who only switch alters after a period of sleep – which is commonly how DID is presented by the media within that country.Proponents of psychotherapy as a cause of DID state that DID is strongly linked to (possibly suggestive) psychotherapy, often involving recovered memories (memories that the person previously had amnesia for) or false memories, and that such therapy could cause additional identities. Such memories could be used to make an allegation of child sexual abuse. There is little agreement between those who see therapy as a cause and trauma as a cause.