“As an undergraduate student in psychology, I was taught that multiple personalities were a very rare and bizarre disorder. That is all that I was taught on ... It soon became apparent that what I had been taught was simply not true. Not only was I meeting people with multiplicity; these individuals entering my life were normal human beings with much to offer. They were simply people who had endured more than their share of pain in this life and were struggling to make sense of it.”

― Deborah Bray Haddock, The Dissociative Identity Disorder Sourcebook

DID Research


Akyüz, G., Doǧan, O., Şar, V., Yargiç, I., & Tutkun, H. (1999). Frequency of dissociative identity disorder in the general population in Turkey. Comprehensive Psychiatry, 40(2), 151-159. doi:10.1016/S0010-440X(99)90120-7

Abstract: This study attempted to determine the prevalence of dissociative identity disorder in the general population. The Dissociative Experiences Scale (DES) was administered to 994 subjects in 500 homes who constituted a representative sample of the population of Sivas City, Turkey. The mean DES score was 6.7+/-6.1 (mean +/- SD). Of the 62 respondents who scored above 17 on the DES, 32 (51.6%) could be contacted during the second phase of the study. They were matched for age and gender with a group of respondents who scored below 10 on the scale, and the Dissociative Disorders Interview Schedule (DDIS) was then administered to both groups. Seventeen subjects (1.7%) received a diagnosis of dissociative disorder according to the structured interview. In the third phase, eight of 17 subjects who had a dissociative disorder on the structured interview could be contacted for a clinical evaluation. They were matched with a nondissociative control group and interviewed by a clinician blind to the structured interview diagnosis. Four of eight subjects were diagnosed clinically with dissociative identity disorder, yielding a minimum prevalence of 0.4%. Dissociative identity disorder is not rare in the general population. Self-rating instruments and structured interviews can be used successfully for screening these cases. Our data, derived from a population with no public awareness about dissociative identity disorder and no exposure to systematic psychotherapy, suggest that dissociative identity disorder cannot be considered simply an iatrogenic artifact, a culture-bound syndrome, or a phenomenon induced by media influences.


Foote, B., Smolin, Y., Kaplan, M., Legatt, M., & Lipschitz, D. (2006). Prevalence of dissociative disorders in psychiatric outpatients. American Journal of Psychiatry, 163(4), 623-629. doi: 10.1176/appi.ajp.163.4.623

Abstract: Objective: The purpose of the study was to assess the prevalence of DSM-IV dissociative disorders in an inner-city outpatient psychiatric population.

Method: Subjects were 231 consecutive admissions (84 men and 147 women, mean age=37 years) to an inner-city, hospital-based outpatient psychiatric clinic. The subjects completed self-report measures of dissociation (Dissociative Experiences Scale) and trauma history (Traumatic Experiences Questionnaire). Eighty-two patients (35%) completed a structured interview for dissociative disorders (Dissociative Disorders Interview Schedule).

Results: The 82 patients who were interviewed did not differ significantly on any demographic measure or on the self-report measures of trauma and dissociation from the 149 patients who were not interviewed. Twenty-four (29%) of the 82 interviewed patients received a diagnosis of a dissociative disorder. Dissociative identity disorder was diagnosed in five (6%) patients. Compared to the patients without a dissociative disorder diagnosis, patients with a dissociative disorder were significantly more likely to report childhood physical abuse (71% versus 27%) and childhood sexual abuse (74% versus 29%), but the two groups did not differ significantly on any demographic measure, including gender. Chart review revealed that only four (5%) patients in whom a dissociative disorder was identified during the study had previously received a dissociative disorder diagnosis.

Conclusions: Dissociative disorders were highly prevalent in this clinical population and typically had not been previously diagnosed clinically. The high prevalence of dissociative disorders found in this study may be related to methodological factors (all patients were offered an interview rather than only those who had scored high on a screening self-report measure) and epidemiological factors (extremely high prevalence rates for childhood physical and sexual abuse were present in the overall study population).


* Horen, S., Leichner, P., & Lawson, J. (1995). Prevalence of dissociative symptoms and disorders in an adult psychiatric inpatient population in Canada.The Canadian Journal of Psychiatry / La Revue Canadienne De Psychiatrie, 40(4), 185-191.

Abstract: Objective: This study attempted to estimate the prevalence of dissociative symptoms and disorders in a Canadian adult psychiatric inpatient population and also attempted to determine the extent to which dissociative disorders were recognized by the attending clinical staff.

Method: All appropriate and consenting adult psychiatric inpatients at the Kingston Psychiatric Hospital in Kingston, Ontario, were given the Dissociative Experiences Scale. Patients scoring 25 or greater were interviewed with the Dissociative Disorders Interview Schedule and the Structured Clinical Interview for DSM-IV Dissociative Disorders. Admission or discharge diagnoses data were used to determine whether or not dissociative disorders were being recognized.

Results: A total of 48 patients completed the Dissociative Experiences Scale and 14 (29%) scored 25 or greater. The prevalence of dissociative disorders in this hospital population was estimated to be 17%. Dissociative identity disorder was found in six percent, dissociative amnesia in eight percent and dissociative disorder not otherwise specified in two percent of the population. These disorders tended to be under-recognized.

Conclusion: Research on more extensive populations is required to establish the true prevalence of dissociative symptoms and disorders in psychiatric inpatients.


* Ross, C., Duffy, C., & Ellason, J. (2002). Prevalence, reliability and validity of dissociative disorders in an inpatient setting. Journal of Trauma & Dissociation, 3(1). doi: 10.1300/J229v03n01_02

Abstract: The authors studied the prevalence and concurrent validity of the dissociative disorders in a private psychiatric hospital inpatient setting over a period of 8 months. All consenting patients admitted over a period of 8 months were administered the 8-item taxometric subscale of the Dissociative Experiences Scale (DES-T) and the Dissociative Disorders Interview Schedule (DDIS) by one interviewer. A second interviewer then administered the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D). Subsequently, a third interviewer conducted clinical diagnostic interviews on subjects positive and negative for dissociative disorders according to the previous interviewers. The second and third interviewers were blind to the results of the preceding interviews. A total of 407 individuals were admitted; of these, 201 completed the DES-T and DDIS; of these, 110 completed the SCID-D; and of these, 50 completed a clinical interview. The lifetime prevalences of dissociative disorders among the interviewed subjects were: DDIS, 40.8%; SCID-D, 44.5%; and clinician, 28.0%. The lifetime prevalences of dissociative identity disorder were: DDIS, 7.5%; SCID-D, 9.1%; and clinician, 10.0%. Kappas for presence of dissociative identity disorder or dissociative disorder not otherwise specified versus no dissociative disorder were: DDIS-DES-T, 0.81; SCID-D-DES-T, 0.76; clinician-DES-T, 0.74; DDIS-SCID-D, 0.74; DDIS-clinician, 0.71; and SCID-D-clinician, 0.56. Kappas for dissociative amnesia and depersonalization disorder were not significant. Dissociative disorders, including dissociative identity disorder, are common in inpatient settings. Chronic, complex dissociative disorders have good concurrent validity. Dissociative fugue is too rare for reliability data to be accumulated. Dissociative amnesia and depersonalization disorder did not demonstrate validity in this study.


Sar, V. (2006). The scope of dissociative disorders: An international perspective. Psychiatric Clinics of North America, 29(1), 227-244. doi:10.1016/j.psc.2005.10.007

Abstract: International research has documented the universality of dissociative. disorders. Not only are dissociative disorders common in various countries but they are also clinically similar in different cultures. Differences may exist, however, between starting points of interest among dissociation researchers in various countries. Beside dissociative identity disorder, somatoform dissociation has been a major study area in The Netherlands, Turkey, and Germany. Dissociative psychosis was the starting point for dissociation studies in Turkey, whereas depersonalization disorder currently is the most studied dissociative disorder in the United Kingdom. The backlash movement remains limited to North America.