Comparison of dissociative identity disorder with other diagnostic groups using a structured interview in Turkey

Comparison of Dissociative Identity Disorder With Other Diagnostic Groups Using a Structured Interview in Turkey L. ilhan Yargl£:, Vedat ~;ar, Hamdi Tutkun, and Behiye Alyanak Twenty patients with dissociative identity disorder (DID), 20 with schizophrenic disorder, 20 with panic disorder, and 20 with complex partial epilepsy were evaluated with the Dissociative Disorders Interview Schedule (DDIS) and the Dissociative Experiences Scale (DES). Subjects with dissociative identity disorder were more frequently diagnosed as having somatization disorder, past or concurrent major depressive episode, borderline personality disorder, depersonalization disorder, and dissociative amnesia than other groups. They reported Schneiderian symptoms and extrasensory perceptions more frequently. In their anamnesis suicide attempts, trance states, sleepwalking, and childhood traumas were more frequent than those in comparison groups. The secondary features of dissociative identity disorder and the DES score differentiated these patients from comparison groups significantly. DID has a set of clinical features different from that of schizophrenic disorder, panic disorder and complex partial epilepsy. The differences are similar to those yielded previously in studies from North America. ISSOCIATIVE IDENTITY DISORDER (DID), also known as multiple personality disorder, ] was thought to be rare until the late 1980s. After its inclusion in DSM-III, 2 it has been diagnosed in North America in increasing frequency. The development of self-report instruments 3,4 and structured clinical interviews, 5,6 which were designed for the assessment of various dissociative disorders, enhanced further evaluation of this diagnostic category. Although there is growing interest in this category among clinicians and researchers of several countries, 7-]3 structured interview data from different cultures are still sparse. First studies conducted with structured interviews in Western Europe 14and Turkey 15yielded symptom profiles similar to those previously 16 reported in North America. DID patients, who had been in the mental health system before the diagnosis of DID was given, usually had several other diagnoses. 17 It seems to be due to the polisymptomatic nature of the disorder that extends beyond its diagnostic criteria defined in the DSM-IV. TM Indeed, it is not uncommon that patients with DID meet DSM-IV diagnostic criteria for several other disorders at the same time, e.g., somatization disorder or borderline personality disorder. 19 However, problems in differential diagnosis are not limited to excessive descriptive comorbidity. Some symptoms such as voices heard inside of the head, black-out spells, and excessive anxiety against covert clues of past trauma can simply lead the clinician to misdiagnose DID patients as schizophrenic disorder, epilepsy, or panic disorder. The purpose of this study was to determine the clinical differences between DID and comparison groups that have been reported as common rnisdiagnoses for DID. A survey among psychiatrists in Turkey showed that most professionals questioned how DID could be reliably differentiated from schizophrenic disorder and complex partial epilepsy. 2°,21 Indeed, schizophrenic disorder and anxiety disorder are among the most common misdiagnoses given to DID cases before correct diagnosis is made. 22We considered these reports in determining the diagnostic categories selected as comparison groups in this study. D Copyright© 1998by W.B. Saunders Company METHODS Subjects The subjects consisted of 20 patients with DID, 20 with panic disorder, 20 with schizophrenic disorder, and 20 with complex partial seizures. The DID cases were patients in the psychiatry clinic of the Istanbul Medical Faculty Hospital, a general medical center with 2,500 beds. All DID patients over 18 years of age who were under evaluation and treatment in the Dissociative Disorders Program during the 3-month study period between May and July of 1994 were considered for participation in the study. Only one case among them was excluded because she had an abnormal EEG. The remaining 20 patients composed the study group. Except for two probands, all DID cases were outpatients. The clinical diagnosis of each DID case was made by the first and third authors initially, and was confirmed by the second author. The first and third authors were senior psychiatry residents and had 2 years of clinical and research experience on dissociative disorders during the study period. The second From the Clinical Psychotherapy Unit and Dissociative Disorders Program, Department of Psychiatry, Istanbul University, Istanbul Medical Faculty Hospital, lstanbul, Turkey. Address reprint requests to L. llhan Yargl6 M.D., Istanbul Ttp Fakiiltesi Psikiyatri Klinigi 34390, ~apa lstanbul, Turkey. Copyright © 1998 by W.B. Saunders Company 0010-440X/98/3906-0010503. 00/0 ComprehensivePsychiatry,Vol. 39, No. 6 (November/December), 1998: pp 345-351 345 346 author, who is a psychiatrist, faculty member, and director of the Dissociative Disorders Program of the clinic, met all the patients separately and confirmed the diagnosis clinically. He also supervised the long-term outpatient and inpatient treatment of the same cohort. To increase the reliability of the diagnosis, intrainterview switching from one personality to another was required for the final decision. Moreover, all of the DID patients met the more strict National Institute of Mental Health (NIMH) research criteria, which required observation of at least two different alter personalities with full-control during at least three different interviews and presence of amnesia between at least two of them in addition to DSM-III-R criteria. 23 Thus, all of the patients also met DSM-IV criteria for DID because they had dissociative amnesia. Subjects with complex partial seizure disorder were recruited from the Epilepsy Unit of either the Department of Neurology, Istanbul University Istanbul Medical Faculty Hospital (n = 8) or the Neurology Clinic, Bakarki3y State Hospital for Nervous and Mental Diseases (n = 12). These subjects had been diagnosed independently by a neurologist, All subjects had EEG findings related to epileptic focus, and they had active seizures at least twice monthly in the last three months before the psychiatric interview. Schizophrenic subjects were recruited from outpatient (n = 9) and inpatient (n = 11) units of our clinic. All of these subjects met DSM-IV criteria for schizophrenic disorder, and had a level of psychological functioning sufficient to cooperate for the study. Subjects with panic disorder (all met DSM-IV criteria) were recruited from the outpatient unit of our clinic, and were interviewed before the treatment. Informed consent was taken from all subjects. To avoid selection bias, the first 20 patients available in each group, who consented to interview, were included in the study. No efforts to match subjects were made. Only one patient with schizophrenic disorder and one with epilepsy refused to participate in the study. Assessment Measures The Dissociative Disorders Interview Schedule. The Dissociative Disorders Interview Schedule (DDIS) is a structured interview consisting of 131 items. 5 It is used to make DSM-III-R diagnoses of somatization disorder, major depressive episode, borderline personality disorder, and all the dissociative disorders. This schedule also inquiries about childhood physical and sexual abuse and a variety of features associated with DID including the following: 11 Schneiderian symptoms, 16 secondary features of dissociative identity disorder, and 16 extrasensory experiences. Two items inquiring about childhood emotional abuse and neglect were added to the Turkish version. The schedule has an overall interrater reliability of 0.68 (kappa), a sensitivity of 90%, and a specificity of 100% for the diagnosis of DID. 5 The DDIS was translated into Turkish independently by the first three authors of the study, and the consensus version was tested on dissociative, nondissociative, and normal subjects to evaluate if it was sufficiently understood. The final version, after the corrections, was used in the study. Interrater reliability and test-retest reliability were evaluated by having two independent interviewers administer the DDIS to 11 patients with dissociative identity disorder and nine patients with a nondissociative psychiatric disorder on two occasions, YARGI(~ ET AL with a minimum 6-month interval between administrations. Kappa value for the diagnosis of DID was 0.80. All of the interviews were administered by the first and third authors, who were experienced in administration of the DDIS. It was conducted by an interviewer other than the clinician who made the initial diagnosis. Because all the authors were working in the same institution where the patients were recruited, it was not possible to keep the interviewer blind to the clinical diagnosis. Association with any other psychiatric disorder or epilepsy was not taken into consideration when making the diagnosis of dissociative amnesia, fugue, and depersonalization disorder, because one of the aims of this study was to determine the extent of the phenomenological overlap between DID and other diagnostic groups, i.e., an epileptic patient reporting amnesia or a schizophrenic patient reporting depersonalization were scored as having these symptoms regardless of the etiology, although DDIS would not allow it so. Otherwise a tautology would occur. The Dissociative Experiences Scale. The Dissociative Experiences Scale (DES) is a 28-item self-report instrument) It serves as a screening instrument, but it is not a diagnostic tool. High scores on the scale suggest, but do not prove, the existence of a dissociative disorder. 3,24.25The Turkish version of the scale has a reliability and validity as good as its original form. 26,27 RESULTS Demographic information for subjects in each group is provided in Table 1. The DID group was the youngest on variance analysis (F = 3.44, df = 3; 76, P < .05). Although DID patients had the highest female-to-male ratio (9/1) among all groups, the difference was not significant (×2 = 7.32, df = 3, P > .05). The rate of marriage was lowest among schizophrenic probands (×2 = 17.9, df= 9, P < .05). They had higher education level than other probands (F = 5.14, df = 3;76, P < .005). The clinical diagnosis of DID was confirmed with the DDIS for 19 patients with the exception of one patient who had dissociative disorder not otherwise specified (DDNOS) on structured interview. One subject with schizophrenic disorder among the controls was diagnosed as having DID on the DDIS. Thus, sensitivity and specificity of the structured interview were 95.0% and 98.3%, respectively. Positive predictive power was 95.0%, and negative predictive power was 98.3% (Table 2). Table 1. Demographic Characteristics of the Subjects Group (n = 20 for each group) DID Female (%) Age (mean -+ SD) Married (%) Education (yr) (mean -+ SD) 90 24.9 -+ 7.0 40 7.5 -+ 3.6 Schizophrenic disorder Panic disorder C o m p l e x partial epilepsy 55 31.7 -4- 8.0 20 11.7 +_ 3.0 55 31.9 -+ 7.6 70 8.1 -+ 4.3 65 31.4 -+ 9.8 55 7.7 +- 4.6 STRUCTURED EVALUATION OF DID 347 Table 2. Relation of Clinical Diagnosis of DID to the DDIS Diagnosis DDIS Clinical Diagnosis Diagnosis Present (n = 20) Present 19 1 20 1 59 60 Absent Absent (n ~ 60) Total (N = 80) NOTE. Yates corrected ×2 = 69.80, d f = 1, P < .00001. The patient diagnosed as having DDNOS on the structured interview reported that he had different personalities within himself, each of which was dominant at a particular time. However, he did not affirm that each personality had distinct features, i.e., behavior and social relationships that are not shared by other personalities. This was due to the amnesia and unawareness of the host personality about the alter personalities. Nevertheless, alter personalities of this patient met during previous sessions had presented different and enduring patterns of perceiving, relating to, and thinking about environment and self. The schizophrenic patient who gave affirmative answers to the questions on diagnostic criteria of DID was a 20-year-old man. He had seven secondary features of DID and met four borderline personality disorder criteria. He described selfmutilative behavior, possession experiences, trans states, and childhood imaginary companionship, which was still going on. He reported physical abuse by his father that had continued until 19 years of age, and childhood emotional trauma. Although this patient reported amnesia between alter personalities, he did not give affirmative answers to direct questions about dissociative fugue, amnesia, and depersonalization disorder. He did not report any somatic complaints either. This is considered a false-positive DID diagnosis on DDIS, because the patient already had clinical features fitting the DSM-IV diagnostic criteria of schizophrenic disorder. The differences between DID and other groups on the main symptom clusters of structured interview and DES scores are shown in Table 3. There were significant differences in all of these items between the DID group and other diagnostic groups. All of the DID subjects reported at least seven secondary features of DID, whereas none of the other subjects had more than seven, 85.0% of the DID subjects, whereas only 8.3% of the other subjects had DES scores above 30. Table 4 shows the differences between the DID group and the other diagnostic groups on the percentages that met DSM-III-R criteria tbr the following: four dissociative disorders, somatization disorder, major depressive episode, and borderline personality disorder. All of these diagnoses were more common in the DID group than in any other group. There were no significant differences between the schizophrenic disorder, panic disorder, and complex partial epilepsy groups on the frequencies of any of these diagnoses. Evaluation of dissociative amnesia was the most intriguing part of assessment. When questioned specifically, 17 probands in the DID group reported that they were aware of the amnesia between their alter personalities. However, only 12 of the DID cases gave an affirmative answer to direct questions inquiring diagnostic criteria of dissociative amnesia on DDIS, despite the observation of intrainterview amnesia in all DID cases. Nevertheless, DID patients gave some indications of amnesia on other items of structured interview, such as being told by others of unremembered events, strangers knowing Table 3. Differences Between DID and Other Groups on the Main Clusters of DDIS DiD Symptom Clusters (n = 20) (mean±SD) Panic Disorder (n ~ 20) Comprex Partial Epilepsy (n = 20) Mean±SD t(df=38) Mean-~SD t(df=38) Mean-SD t(df=38) 2.1±2.0 12.25 2.3_+1.9 12.15 0.5_+0.5 18.15 Extrasensory experiences 4.0 _+ 2.6 1.8 _+ 2.2 2.9/- 1.0 _+ 1.1 4.8:1: 0.9 _+ 1.4 4.75 No. o f Schneiderian s y m p t o m s 6.3 _+ 1.8 4.3 ± 2.9 2.6* 0.2 -+ 0.7 14.35 0.4 ± 0.8 13.6$ 13.2 ± 5.4 2.1 ± 2.1 8.65 3.5 + 5.3 6.835 3.6 ± 3.4 3.9 + 2.0 1.4 ± 1.6 4.3¢ 0.6 ± 0.9 6.6$ 1.7 ± 1.6 3.71- 15.6 + 2.7 6.25 8.5 _+ 8.0 8.6$ 12.8 + 10.4 7.25 Secondary features o f DID No. o f somatic c o m p l a i n t s No. of borderline personality disorder criteria m e t DES score Abbreviation: NS, not significant. * P < .05. tP< .01. ¢ P < .0001. 11.0+2.5 Schizophrenic Disorder (n -- 20) 46.1 -+ 17.9 6.735 348 YARGI(~ ET AL Table 4. Differences Between DID and Other Groups on DDIS Subdiagnoses Diagnosis Major depressive episode (current or past) Borderline personality disorder Sornatization disorder Psychogenic amnesia Psychogenic fugue Depersonalization disorder Multiple personality disorder DID Schizophrenic Disorder (n = 20), (n = 20) No. Positive No. Positive ×2(df= 1) Panic Disorder (n = 20) Complex Partial Epilepsy (n = 20) No. Positive ×2(df= 1) No. Positive ×2(df= 1) 17 7 10.42" 6 12.381- 6 12.381- 7 11 12 4 15 19 0 0 1 0 1 1 Fisher's exact* 15.175 13.701Fisher% exact(NS) 25.895 32.45 0 0 0 0 1 0 Fisher's exam* 15.175 17.145 Fisher% exact(NS) 25.895 36.195 g 0 4 0 3 O Fisher's exam* 15.17t 6.67* Fisher% exact(NS) 19.80t 36.19t * P < .01. t P < .001. $P < .0001. the patient, coming out of a blank spell in a strange place, as inquired among the secondary features of DID. The differences between the study groups on a number of mental health history items are shown in Table 5. There were significant differences on childhood sexual abuse, trance states, and sleepwalking between DID patients and comparison groups. Chronic severe headache and childhood physical or emotional abuse differentiated the DID group from the schizophrenic disorder and panic disorder group, but not from the complex partial epilepsy group. Self-mutilative behavior differentiated in DID patients from other groups except patients with schizophrenic disorder. Frequencies of extrasensorial perception and supernatural experiences in each group are shown in Table 6. Only possession experiences differentiated DID patients from all other groups. Contact with spirits differentiated DID patients from other groups except for patients with schizophrenic disorder. Reincarnation and cult experience did not differ any group from others. DISCUSSION To our knowledge, this is the first study in Turkey that compares subjects with DID with other diagnostic categories using structured interview data. Our findings suggest that DID patients can be differentiated from subjects with schizophrenic Table 5. Differences Between DID and Other Groups on Some Mental Health History Items of the DDIS Item Headache Sleep walking Trance states Childhood imaginary companionship Substance abuse Suicide attempts Self-mutilative behavior Childhood sexual abuse Childhood physical abuse Childhood physical and/or sexual abuse Childhood emotional abuse Childhood neglect *P< tP< SP< §P< .05. .01. .001. .0001. DID Schizophrenic Disorder (n = 20), (n = 20) No. Positive No. Positive ×Z(df= 1) Panic Disorder (n = 20) Complex Partial Epilepsy (n = 20) 1) No. Positive ×2(dr= 1) No. Positive 10 3 4 3.96* 6.09* 26.78§ 12 3 12 1.90 (NS) 6.09" 10.581- x2(df = 16 8 19 7 3 7 6 1 16 11 14 12 2 3 9 5 4 4 4.29 (NS) Fisher's exact (NS) 5.23* 3.75 (NS) 10.41 t 6.67T 0 1 1 0 g 2 11.61t Fisher's exact (NS) 23.02§ 15.205 21.54§ 10.995 1 0 3 1 3 6 5.06 (NS) Fisher's exact (NS) 16.94§ 11.905 12.38$ 3.64 (NS) 16 12 13 8 3 8 6.675 9.531" 2.51 (NS) 2 3 4 19.80§ 9.53t 8.291" 8 6 8 6.67t 3.64 (NS) 2.51 (NS) 8.29t 6.09* 19.54§ STRUCTURED EVALUATION OF DID 349 Table 6. Differences Between DID and Other Groups on Extrasensory Experiences DID(n = 20) Item Panic Disorder (n = 20) Schizophrenic Disorder (n = 20) No. Positive No. Positive ×2 ( d f = 1) 13 5 7.11" 1 Contact with spirits 7 2 Fisher~ exact(NS) 0 Reincarnation 4 1 Fisher's exact(NS) 3 18 1 10 Fisher's exact(NS) 7.62t Possession Cult/sect experiences Any extrasensory perception No. Positive ×2(df= 1) Complex Partial Epilepsy(n = 20) No. Positive ×z (df = 1) 8.49t 1 O 17.97$ 8.491" 0 2.5(NS) 1 Fisher's exact (NS) 4 10 0.2(NS) 7.62t 1 8 Fisher's exact (NS) 10.995 20.5§ Abbreviation: NS, not significant. * P < .05. TP < .01. :I:P< .001. § P < .0001. disorder, panic disorder, and complex partial epilepsy using a structured interview. Moreover, the differences between DID cases and comparison groups in the main items of the interview were similar to the findings reported in North America.28, 29 In our study, one patient with schizophrenic disorder among the control subjects was diagnosed as having DID on the DDIS. Ross et al5 reported that only four subjects among 500 schizophrenic patients had been diagnosed as having DID on the DDIS. Having alter personalities may be considered as a delusion for the patient in our study. On the other hand, this patient reported childhood traumas that have been shown as interrelated with dissociative experiences, independent of the main diagnosis among general psychiatric patients 3°-32 and nonclinical populations. 33,34 Ross 35 even suggests a dissociative subtype of schizophrenic disorder. This issue needs further investigation. There was a discrepancy about dissociative amnesia between clinical observation and structured interview. This discrepancy was apparently caused by the phenomenon called "amnesia for amnesia. ''36 These findings suggest that direct questioning of dissociative amnesia does not always yield reliable results, rather indirect cues of amnesia should be searched. On the other hand, patients with chronic dissociative disorders with distinct personality states can show different characteristics on state measures, whereas they report relatively consistent features on trait measures. Dissociative amnesia seems to be a state dependent characteristic, whereas some indirect cues of the disorder, i.e., secondary features of the disorder, are relatively enduring characteristics that do not drastically change depending on identity alteration. In our study, a history of depersonalization disorder, and past or concurrent major depressive episodes, differentiated the patients with DID from other groups. In the Ross et al study, 28 these items did not have any significant differences between DID, schizophrenic disorder, and panic disorder groups. In fact, the discrepancy between two studies depends rather on the higher frequency of major depressive episodes and depersonalization disorder in the Ross et al. control groups compared with ours. The rates of these items are similar for DID patients in both studies. Depending on their results, Ross et al. questioned the existence of depersonalization disorder as a specific clinical entity, and suggested that it is only a symptom that may be seen in various psychiatric populations. Our results do not support the Ross et al. opinion. There are several reports 16,17,22,37,38 in North America that suggest high incidence of alcohol and substance abuse among DID subjects. However, there was only one substance abuser in our DID group, and the frequency of alcohol or substance abuse did not differentiate the DID group from the others. The low rate of substance and alcohol abuse in our DID patients may be due to their relatively low frequency in the general population in Turkey. Unfortunately, there is not any reliable epidemiological data for substance and alcohol abuse in our country. In our study, the feeling of being reincarnated and cult experiences did not differ DID group from the others. Neither belief of reincarnation nor satanic cults are known to be common in Turkey. Different results about alcohol or substance abuse, feeling of being reincarnated, and cult experiences may show a cultural variation. However, our study group consists of cases who admitted to a univer- 350 YARGI~: ET AL sity clinic; the cases in other institutions, or in the community, may differ in these characteristics. Frequency of childhood sexual and physical abuse reported by our DID subjects is within the same range as the frequencies reported in five large DID case series reported in North America16,17,22,37,38: 60% to 82% physical abuse, 68% to 90% sexual abuse. As most of the DID subjects in this study were at the beginning phase of their treatment, they might have hidden their trauma history from the interviewer, or they might still be amnesic about their childhood traumas. We did not include here the trauma histories of some DID subjects that were reported after the study interview, therefore, these are rather minimum numbers of childhood abuse histories of the DID subjects. However, we have the impression that the childhood trauma histories in most of our DID patients were not as brutal as those reported from North America. This study focused on misdiagnosis of DID; however, excessive descriptive comorbidity is another problem for DID eliciting interesting questions for future research on nosology and classification. In a consecutive screening study, the most frequently accompanying psychiatric diagnoses were past or current depressive episode, somatization disorder, and borderline personality disorder. 19 These patients will continue to have several concurrent diagnoses, because the diagnostic criteria for these categories do not exclude each other. On the other hand, the excessive descriptive comorbidity might be reflecting different faces of a single multifaceted psychiatric condition, the clinical expression of adult psychopathology related to childhood trauma. 39,4° Differentiation of these disorders from DID should be studied further. The interviewers o f this study were not blind to the diagnoses. However, the DDIS is highly structured to minimize and control for demand characteristics of the interviewer. Moreover, the patients were assessed both by self-report and structured interview in this study. In conclusion, diagnostic criteria, clinical phenomenology, and historical properties of DID described in North America can also differentiate this disorder from schizophrenic disorder, panic disorder, and complex partial epilepsy in Turkey. Although limited to the diagnostic groups selected for comparison, the present study provides crosscultural support for the validity of the DDIS. REFERENCES 1. American PsychiatricAssociation.Diagnostic and Statistical Manual of Mental Disorders. (Ed. 4). Washington, DC: American PsychiatricAssociation, 1994. 2. American PsychiatricAssociation.Diagnostic and Statistical Manual of Mental Disorders. (Ed. 3). Washington, DC: American PsychiatricAssociation, 1980. 3. Bernstein EM, Putnam PW. Development, reliability and validity of a dissociation scale. J Nerv Ment Dis 1986;174:727735. 4. Vanderlinden J, Van Dyck R, VandereyckenW, Vertommen H, Verkes RJ. The Dissociation Questionnaire (DIS-Q): Development and characteristics of a new self-reporting questionnaire. Clin Psychol Psychother 1993;1:21-27. 5. Ross CA, Heber S, Norton GR, Anderson D, Anderson G, Barchet P. The dissociative disorders interview schedule: A structured interview. Dissociation 1989;2:169-189. 6. Steinberg M. Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised (SCID-D-R). Washington, DC: American Psychiatric Press, 1994. 7. Adityanjee R, Raju G, Khandelwal S. Current status of multiplepersonalitydisorderin India.Am J Psychiatry 1989;146: 1607-1610. 8. TakahashiY. Is multiple personality disorder really rare in Japan? Dissociation 1990;3:57-59. 9. Martinez-TaboasA. Multiple personality in Puerto Rico: An analysis of fifteen cases. Dissociation 1991;4:189-192. 10. Modestin J. Multiple personality disorder in Switzerland. Am J Psychiatry 1992;149:88-92. 11. Knudsen H, Haslernd J, Boe T, Draljer N, Boon S. Prevalence of dissociative disorders in a Norwegian general psychiatric department (inpatients and daycare). In: van der Hart O, Boon S, Draijer N (eds): Proceedings of the Fifth Spring Meeting of the International Society for the Study of Dissociation. Amsterdam,Holland: International Society for the Study of Dissociation, 1995:79. 12. Tutkun H, Yargl~LI Sar V. Dissociative identity disorder: A clinical investigation of 20 cases in Turkey. Dissociation 1995;8:3-9. 13. VanderlindenJ, VargaK, Peuskens J, Pieters G. Dissociative symptoms in a population sample of Hungary. Dissociation 1995;8:205-208. 14. Boon S, Draijer N. Multiple personality disorder in the Netherlands: A clinical investigation of 71 patients. Am J Psychiatry 1993;150:489-494. 15. Sat V, Yargl~H, Tutkun H. Structured interview data on 35 cases of dissociative identity disorder in Turkey. Am J Psychiatry 1996;153:1329-1333. 16. Ross CA, Miller SD, Reagor P, Bjornson L, Fraser GA, Anderson G. Structured interview data on 102 cases of multiple personality disorder from four centers. Am J Psychiatry 1990; 147:596-601. 17. Putnam FW, Guroff JJ, Silberman EK, Barban L, Post RM. The clinical phenomenology of multiple personality disorder: Review of 100 recent cases. J Clin Psychiatry 1986;47:285293. 18. American PsychiatricAssociation. Diagnostic and Statistical Manual of Mental Disorders. (Ed. 4). Washington, DC: American PsychiatricAssociation, 1994. STRUCTURED EVALUATION OF DID 19. Tutkun H, ~ar V, Yargl~ LI, 0zpulat T, Yamk M, Klzdtan E. Frequency of dissociative disorders among psychiatric inpatients in a Turkish university clinic. Am J Psychiatry 155:800805. 20. ~;arV, Yargl~, Li, Tutkun H. Current status of dissociative identity disorder in Turkey. In Proceedings of the Fifth Spring Conference of the International Society for the Study of Dissociation. Edited by van der Hart O, Boon S, Draljer N. Amsterdam, International Society for the Study of Dissociation, 1995, p. 76. 21. ~ar V, Yarglq LI, Tutkun H. The experiences and opinions of psychiatrists on multiple personality disorder in Turkey (Written in Turkish)• N/~ropsikiyatri Ar~ivi. 1995 ;32:76-83• 22. Ross CA, Norton GR, Wozney K. Multiple personality disorder: An analysis of 236 cases. Can J Psychiatry 1989;34:413418• 23. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. (Ed. 3). Washington, DC: American Psychiatric Association, 1987. 24. Carlson EB, Putnam FW. An update on Dissociative Experiences Scale• Dissociation 1993;6:16-27• 25. Carlson EB, Putnam FW, Ross CA, Torem M, Coons P, Dill DL, et al. Validity of the Dissociative Experiences Scale in screening for multiple personality disorder: A multicenter study. Am J Psychiatry 1993;150:1030-1036• 26. Yarglq LI, Tutkun H, Sar V. Reliability and validity of the Turkish version of the Dissociative Experiences Scale. Dissociation 1995;8:10-12. 27. ~ar V, Kundak~l T, Klzdtan E, Baklm B, Yargl~ LI, Tutkun H. The reliability and validity of the Dissociative Experiences Scale (DES-H). Proceedings of the 33th National Congress of Psychiatry (Written in Turkish), Antalya, Turkey; 1997:55-64. 28. Ross CA, Heber S, Norton GR, Anderson D. Differences between multiple personality disorder and other diagnostic groups on structured interview. J Nerv Ment Dis 1989;177:487491. 29. Ross CA, Heber S, Anderson G, Norton GR, Anderson BA, del Campo M, et al. Differentiating multiple personality disorder and complex partial seizures. Gen Hosp Psychiatry 1989;11:54-58. 351 30. Chu JA, Dill LD. Dissociative symptoms in relation to childhood physical and sexual abuse• Am J Psychiatry 1990;147: 887-892. 31. ~ar V, Tutkun H, Alyanak B, Baklm B, Baral I. Frequency of childhood abuse among psychiatric outpatients in Turkey. Program Book of the 13th Annual Conference of the International Society for Traumatic Stress Studies, 1997; 131. 32. Tutkun H, ~ar V, Yarglq, LI, Ozpulat T, Yanlk M, Ktzlltan E. Frequency of childhood abuse among psychiatric inpatients in Turkey. Programbook of the 13th Fall Conference of the International Society for Traumatic Stress Studies, 1997; 131. 33. Yarglq Li, Tutkun H, Sar V. Childhood abuse and dissociative experiences in adulthood. In: van der Hart O, Boon S, Draijer N (eds): Proceedings of the Fifth Spring Conference of the International Society for the Study of Dissociation. Amsterdam, The Netherlands: International Society for the Study of Dissociation, 1995;84. 34. Zoro~lu S, TUztin U, ~ar V, Ertcal-Kora M, Oztiirk M, Alyanak B. Childhood abuse, self-injury and dissociative experiences among high-school students. Program Book, 13th Fall Conference of the International Society for the Study of Dissociation• Glenview, IL, International Society for the Study of Dissociation, 1996;285. 35. Ross CA. Dissociative Identity Disorder. Diagnosis, Clinical Features, and Treatment of Multiple Personality. New York, NY: Wiley, 1997;196. 36. Kluft RP. The dissociative disorders• In: Talbot JA, Hales RE, Yudofsky SC (eds): Textbook of Psychiatry. Washington, DC: American Psychiatric Press, 1988:557-584. 37. Coons PM, Bowman ES, Milstein V. Multiple personality disorder: A clinical investigation of 50 cases. J Nerv Ment Dis 1988; 176:519-527. 38. Schultz R, Braun BG, Kluft RP. Multiple personality disorder: Phenomenology of selected variables in comparison to major depression• Dissociation 1989;2:45-51. 39. Herman JL. Trauma and Recovery. Basic Books, New York, NY: 1992. 40. Herman JL, Perry CJ, van der Kolk B. Childhood trauma in borderline personality disorder. Am J Psychiatry 1989;146:490495.