Schneiderian Symptoms in Multiple Personality Disorder and Schizophrenia Colin A. Ross, Scott D. Miller, Pamela Reagor, Lynda Bjomson, George A. Fraser,
and Geri Anderson We report structured interview data from a series of 102 cases of multiple personality disorder (MPD) diagnosed in four centers. Schneiderian first-rank symptoms of schizophrenia were equally common in all four centers. The average MPD patient had experienced 6.4 Schneiderian symptoms. When these 102 cases are combined with two previously reported series of MPD cases, an average of 4.9 Schneiderian symptoms in 368 cases of MPD is noted. This compares with an average of 1.3 symptoms acknowledged by 1,739 schizophrenics in 10 published series. Schneiderian symptoms are more characteristic of MPD than of schizophrenia. 0 1990 by W. 8. Saunders Company.
CHNEIDERIAN FIRST-RANK SYMPTOMS of schizophrenia are common in multiple personality disorder (MPD).‘*2 They differentiate MPD from eating disorders and panic disorder3 and from complex partial seizure disorder.4 In the only study comparing MPD patients with schizophrenics, however, there was no significant difference between the number of Schneiderian symptoms reported by 20 MPD patients and the number reported by 20 schizophrenics on structured interview.3 In a series of 236 cases of MPD reported to them by 203 clinicians throughout North America, Ross et al.’ observed an average of 4.5 Schneiderian symptoms of schizophrenia per patient. In a series of 30 cases, Kluft’ reported an average of 3.6 Schneiderian symptoms per patient. This report compares the frequency of Schneiderian symptoms in two large series of MPD patients to determine whether they are consistent across series. The frequency of Schneiderian symptoms in MPD is then compared with that in schizophrenia.
S
METHOD
Subjects Subjects in the first series are 236 cases of MPD reported to us by 203 clinicians throughout North America who jointly had seen 1,807 patients with MPD. Subjects in the second series are 102 patients with MPD from four centers, Winnipeg (N = 50), Utah (N = 20), California (N = 17), and Ottawa (N = 15). These subjects received their clinical diagnoses from a psychiatrist and/or research nurse in Winnipeg, from a psychologist in Utah, from an M.A. psychological assistant or a Ph.D. psychologist in California, and from a psychiatrist in Ottawa. Of the 50 patients reported from Winnipeg, four were assessed clinically only by the research nurse, who has extensive experience with both MPD and schizophrenia, and 46 were assessed by the psychiatrist.
From the Department of Psychiatry, University of Manitoba; Canyon Springs Hospital. Cathedral City. CA: Heuler, Reagor and Associates, Orange, CA; the Department of Psychiatry, University of Ottawa. Canada; and St. Boniface Hospital, Winnipeg, Manitoba, Canada.
Address reprint requests to Colin A. Ross, M.D., Department of Psychiatry, St. Bonifnce Hospital 409 Tache Ave., Winnipeg, Manitoba, R2H 2A6 Canada. 0 1990 by W.B. Saunders Company. 0010-440X/90/31 02-0005S03.00/0
Comprehensive Psychiatry, Vol. 3 1, No. 2 (March/April),
1990: pp 1 1 1- 7 18
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Procedure The first series of 236 cases was gathered by mailing a 36-item questionnaire on MPD to 1,729 members of the Canadian Psychiatric Association and to 5 15 members of the International Society for the Study of Multiple Personality and Dissociation. Each respondent was asked to complete the questionnaire on a recent case of MPD he had seen, or to indicate that he had not made a diagnosis of MPD. The questionnaire inquired about diagnostic criteria for MPD and a range of associated features. The second series was gathered by completing the Dissociative Disorders Interview Schedule (DDIS) on patients with a clinical diagnosis of MPD in each of the four centers. The DDIS is a 131-item structured interview which takes 30 to 45 minutes to administer for most patients. It has an interrater reliability of 0.68, good validity, and a sensitivity of 90% and specificity of 100% for the diagnosis of MPD.6 In Winnipeg, subjects were the first 50 patients with MPD diagnosed in the Dissociative Disorders Clinic at that center, and almost all completed the DDIS at the time of initial assessment. The procedure in Winnipeg was for the research nurse to complete the DDIS before clinical assessment was made. In Utah, subjects were interviewed consecutively in conjunction with a Ph.D. thesis study of MPD in which they agreed to participate as subjects. In California, subjects were interviewed consecutively as they presented for clinical assessment. In Ottawa, subjects were drawn from an existing caseload, and primarily included patients in therapy. No interviewers were blind to the clinical diagnoses. No investigators at any of the centers had met patients diagnosed at other centers. No MPD subjects were included in both series. The raw DDIS data were sent to the coordinating center for the study and entered and analyzed there. Although the data in Tables I through 5 are presented as percentages for ease of understanding, all responses described consisted of dichotomous yes or no answers. Therefore, chi squares were used in the analysis; t tests were used to analyze continuous variables reported below. Significance was set at P c.05. The literature on Schneiderian symptoms in schizophrenia was reviewed,?-24and the figures in Tables 3 through 5 were tabulated based on the published reports. The overall frequency and the prevalence of Schneiderian symptoms in schizophrenia were then calculated. Because not all series of schizophrenics included information on both the prevalence and the average number of Schneiderian symptoms per patient, not all series appear in both Tables 4 and 5. For some series of schizophrenics, either the frequency or prevalence of Schneiderian symptoms could be calculated from the data presented and, if so, that information is included in this report. Because only three reports”,‘*,” gave a frequency distribution of Schneiderian symptoms in schizophrenia, only those three series are reported in Table 3.
RESULTS
The subjects in the first MPD series (N = 236) had a mean age of 30.1 years (SD. 8.0), and 87.7% were female. The subjects in the second MPD series (N = 102) had a mean age of 31.8 years (S.D. 8.3), and 90.2% were female. Subjects in the two series did not differ in age (t = 1.78, NS), or sex (x2 (1) = 1.37, NS). In the first series, 37.0% of the subjects were married, 37.4% single, 23.4% separated or divorced, and 1.7% widowed and had a mean of 1.2 children (S.D. 1.4). Of the subjects in the second series 3 1.4% were married, 49.0% were single, 18.6% were separated or divorced, and 1.O% was widowed; the subjects had a mean of 1.O children (S.D. 1.4). Subjects in the two series did not differ in number of children (t = 1.21,NS). As shown in Table 1, 40.8% of subjects in the first series had received a previous diagnosis of schizophrenia, as compared with 25.6% in the second (x2 (1) = 7.12, P -C .008). Of the subjects in the first series, 54.5% had been prescribed an antipsychotic, as compared with 57.0% in the second (x2 (1) = 0.32, NS). Of the subjects in the first series, 12.1% had received electroconvulsive shock therapy (ECT) as compared with 16.7% in the second (x2 (1) = 1.16, NS).
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Table 1. Frequency of a Previous Diagnosis of Schizophrenia and Treatment Neuroleptics and ECT in Two Series of MPD Patients
With
Series 1 (%I (N = 236)
Series 2 (%I (N = 102)
P
40.8
26.5
.008
54.5 12.1
57.0 16.7
NS NS
Previous diagnosis of schizophrenia Treatment with antipsychotic medication Treatment with ECT
Abbreviation: ECT, electroconvulsive shock therapy; NS, not significant.
The frequencies of the 11 Schneiderian symptoms in the two series are shown in Table 2. Statistical information for each of these comparisons is as follows: voices commenting (x2 (1) = 5.44, P < .02), voices arguing (x2 (1) = 1.87, NS); thoughts ascribed to others (x2 (1) = 26.41, P < .OOOOl), made feelings (x2 (1) = 22.69, P < .OOOOl),made acts (x2 (1) = 11.35, P < .OOOl),audible thoughts (x2 (1) = 6.38, P < .02), made impulses (x2 (1) = 3.69, NS), delusions (x2 (1) = 2.48, NS), thought withdrawal (x2 (1) = 6.03, P < .02), external influences (x2 (1) = 2.77, NS), and thought broadcasting (x2 (1) = 15.34, P < .OOOl). The average number of Schneiderian symptoms per patient was 4.5 (S.D. 3.3) in the first series and 6.4 (S.D. 7.3) in the second (t = 3.30, P < .Ol). As shown in Table 3,80.1% of subjects in the first series and 99.0% of subjects in the second had experienced one or more Schneiderian symptoms. Of the 102 subjects in the second series, 90.2% had experienced three or more Schneiderian symptoms. In another section of the DDIS dealing with secondary features of MPD, subjects are asked if they ever hear voices: Of the 89 subjects (87.3%) who said they did, 84 (94.4% of those hearing voices) said that they came from inside the head. There were no significant differences between MPD subjects at the four centers in the second series (N = 102) on any of the data in this report (P < .05). The frequency distribution of Schneiderian symptoms in 102 MPD patients and three series of schizophrenics is shown in Table 4. Fifty-four (52.9%) of the MPD patients, but only 16 (4.4%) of the schizophrenics, had experienced more than six Schneiderian symptoms. Table 2. Frequency
of Schneiderian First-Rank Symptoms Series of MPD Patients
Symptom Voices commenting Voices arguing Thoughts ascribed to others Made feelings Made acts Audible thoughts Made impulses Delusions Thought withdrawal External influences Thought broadcasting Abbreviation: NS, not significant.
Series 1 (96) (N = 236) 66.1 71.7 36.9 36.2 43.5 45.6 46.3 45.0 29.2 44.7 13.0
of Schizophrenia
Series 2 (%I (N = 102) 81.4 78.4 67.6 64.7 63.7 60.8 57.8 53.9 43.1 35.3 31.4
in Two
P .02 NS .00001 .00001 .0008 .02 NS NS .02 NS .OOOl
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ROSS ET AL
Table 3. Prevalence
of Schneiderian Symptoms in 12 Series of Schizophrenics Series of MPD Patients Percentage of Subjects With One or More Symptoms
Reference Schizophrenia 7 (N = 166) 8 (N = 34) 9 (N = 103) 10 (N = 71) 11 (N = 811) 12(N = 810) 13 (N = 210) 14 (N = 92) 15 (N = 50) 16 (N = 100) 18 (N = 51) 19 (N = 55) Total (N = 2,576) MPD 1 (N = 30) 5 (N = 236) Present study (N = Total (N = 368)
and Three
71.7 64.7 51.5 33.8 57.5 51.9 32.9 56.5 88.0 82.0 72.5 73.2 55.5 100.0 80.1 99.0 87.0
102)
The average number of Schneiderian symptoms per patient in 10 series of schizophrenics and three series of MPD patients are shown in Table 5. The prevalence of Schneiderian symptoms in 12 series of schizophrenics and three series of MPD patients are shown in Table 3. DISCUSSION
The findings from two large series confirm that Schneiderian symptoms are common in MPD. Voices commenting and voices arguing are the two most common Table 4. Frequency
Distribution of Schneiderian Symptoms and 361 Schizophrenics
Schizophrenia
MPD
No. of Symptoms Positive 0 1
2 3 4 5 6 7 8 9 10 11
Present Study
Koehler et al.
N
(N = 210) N
1 3 6 9 11 8 10 16 11 11 10 6
141 27 20 11 7 2 2 0 0 0 0 0
(N =
102)
in 102 MPD Patients
Gharagozlou and Behin
Ndetei and Singh
(N = N
(N = 51) N
18 9 14 13 12 15 13 6 0 0 0 0
14 11 3 4 6 3 1 3 4 0 1 2
100)
.
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MULTIPLE PERSONALITY AND SCHIZOPHRENIA
Table 5. Average No. of Schneiderian Symptoms Per Patient in 10 Series of Schizophrenics and Three Series of MPD Patients Average No. of Symptoms
Reference Schizophrenia 7 (N = 166) 9 (N = 103) 11 (N = 811) 13 (N = 210) 14 (N = 92) 15 (N = 50) 16 (N = 100) 17 (N = 100) 18 (N = 51) 19 (N = 56) Total (N = 1,739) MPD 1 (N = 30) 5 (N = 236) Present study (N = Total (N = 368)
1.3 1.4 1.0 0.7 1.7 1.8 1.6 1.7 3.1 2.4 1.3
102)
3.6 4.5 6.4 4.9
symptoms in both series. This is consistent with the clinical understanding of MPD, in which the voices are recognized to be those of alter personalities.’ In the series of 102 MPD cases, 94.4% of subjects hearing voices said that they came from inside the head. This is believed to be a feature of MPD auditory hallucinations which differentiates them from those of schizophrenia. Schizophrenic voices tend to come from outside the head. The data in the three MPD series were gathered in different ways. One series (N = 236) was generated by having 203 respondents complete a questionnaire mailed to them. The second series (N = 30) was generated by careful clinical interview and chart review by a single clinician reviewing his own caseload. The third series (N = 102) was generated by having professionals at four centers with a specialty interest in MPD administer a structured interview to their patients. In Utah the patients were subjects for a Ph.D. thesis, in Winnipeg and California they were interviewed consecutively at the time of initial assessment, and in Ottawa most patients were in treatment. Despite this variation in the timing and purpose of the structured interviews in the third series, there were no differences between centers on the demographic characteristics, or the mean number of Schneiderian symptoms endorsed. The findings indicate that Schneiderian symptoms are reported in a consistent fashion by MPD patients throughout North America and that their acknowledgment of these symptoms does not differ whether they are research subjects, treatment cases, or interviewed at the time of assessment for MPD. The degree of variation between the two large MPD series on individual Schneiderian symptoms is similar to that observed when different series of schizophrenics are compared.20~2’ We do not believe that this degree of variability has any conceptual importance. The DDIS does not result in an indiscriminate acknowledgment of Schneiderian symptoms by clinical subjects. The average number of Schneiderian symptoms acknowledged on the DDIS by patients with panic disorder is 0.3,3 with eating
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disorders 1.7,3 with complex partial seizures 0.5,4 and with other neurological disorders 0.3.4 One cannot argue that the rate of Schneiderian symptoms in MPD is an artifact of the DDIS, and it was used in only one of the three MPD series described in Tables 1 through 5. When the three available series of MPD patients for whom Schneiderian symptoms have been tabulated are compared with published series of schizophrenics, it is clear that MPD patients consistently experience more of these symptoms than do schizophrenics. Indeed, 52.9% of MPD patients but only 4.4% of schizophrenics have experienced more than six Schneiderian symptoms. Both the average number of Schneiderian symptoms per patient and the prevalence of patients with one or more symptoms are higher in MPD than in schizophrenia: There was no overlap between the MPD and schizophrenia series on the average number of symptoms per patient and only a small amount of overlap on the prevalence. When the three series of MPD cases are totaled (N = 368), the average number of Schneiderian symptoms per patient is 4.9 compared with an average of 1.3 for 1,739 schizophrenics. This finding, together with the frequency distribution of Schneiderian symptoms described in Table 3, demonstrates that the greater the number of Schneiderian symptoms reported by a patient, the more likely the diagnosis is MPD and the less likely it is schizophrenia. We, and Kluft,’ were aware of the need to differentiate MPD from schizophrenia25*26 and carefully ruled out schizophrenia in their clinical assessments. The same is likely true of most repondents in the series of 236 cases of MPD: All cases in this series met DSM-III-R criteria for MPD. We are confident that the 368 cases of MPD are not contaminated by unrecognized cases of schizophrenia. The inverse does not hold, however. There is no evidence that any of the investigators reporting series of schizophrenics considered MPD in their clinical assessments, and none of their instruments make dissociative diagnoses. As shown in Table 1, many MPD patients have been misdiagnosed as schizophrenic and treated with neuroleptics and ECT.2 This raises the question of whether reported series of schizophrenics are contaminated by a significant number of undiagnosed MPD patients. The likelihood that this is true hinges on the prevalence of MPD, which has not been determined. According to one estimate, 6,000 patients with MPD had been diagnosed in North America by 1986. 27 The respondents reporting the series of 236 cases of MPD had jointly seen 1,807 patients. This information alone suggests that MPD is not rare. Based on our own clinical experience, preliminary screening studies in clinical and nonclinical populations,28 and our reading of the literature, we suspect that MPD has a point prevalence greater than 1 in 1,000 adults in North America. If this is true, a significant contamination of schizophrenic research series by undiagnosed MPD patients is likely to have occurred in the last two decades. The average number of Schneiderian symptoms in schizophrenia may actually be less than 1.3, if all cases of MPD are excluded. Because Schneiderian symptoms are relatively uncommon in schizophrenia, they may be specific for a subtype of schizophrenia and not for the heterogeneous group of schizophrenias as a whole. Whether schizophrenics with a large number of Schneiderian symptoms have higher rates of childhood trauma and of other dissociative symptoms than
MULTIPLE PERSONALITY AND SCHIZOPHRENIA
117
schizophrenics with no Schneiderian symptoms will be important to determine. There may be a dissociative subtype of schizophrenia with distinct premorbid features, onset, symptoms, treatment response, and prognosis. The present data only hint at this possibility, but systematic investigations could be conducted with the DES and DDIS. At present, any patient with Schneiderian symptoms should be assessed for a history of childhood abuse, amnesia in one or more forms, and MPD. The evidence from two large series suggests that a considerable number of patients in North America may have been given false-positive diagnoses of schizophrenia and false-negative diagnoses of MPD. Because the treatments of the two disorders differ radically, it is important to differentiate between schizophrenia and MPD carefully and systematically. This can be done using the DES, and DDIS, and/or a clinical interview which makes a specific inquiry for symptoms present in MPD and absent in schizophrenia. Preliminary evidence suggests that hypnotizability testing can also differentiate MPD from schizophrenia, with dissociative patients scoring higher.2g Tools to differentiate MPD from schizophrenia with good reliability and validity are available in the literature. Previous studies have shown that Schneiderian symptoms are not pathognomonic for schizophrenia and occur in other psychiatric disorders and in normal controls.23 The present study indicates that they are better described as first-rank symptoms of MPD than of schizophrenia. REFERENCES 1. Kluft RP: First-rank symptoms as a diagnostic clue to multiple personality disorder. Am J Psychiatry 144:293-298, 1987 2. Ross CA, Norton CR: Multiple personality patients with a past diagnosis of schizophrenia. Dissociation 1:39-42, 1988 3. Ross CA, Heber S, Anderson G, et al: Differences between multiple personality disorder and other diagnostic groups on structured interview. J Nerv Ment Dis 177:487-491, 1989 4. Ross CA, Heber S, Anderson G, et al: Differentiating multiple personality disorder and complex partial seizures. Gen Hosp Psychiatry 11:54-58,1989 5. Ross CA, Norton GR, Wozney K: Multiple personality disorder: An analysis of 236 cases. Can J Psychiatry 34:413-418, 1989 6. Ross CA, Heber S, Norton GR, et al: The dissociative disorders interview schedule: A structured interview. Dissociation (in press) 7. Mellor CS: First rank symptoms of schizophrenia. Br J Psychiatry 117:15-23, 1970 8. Taylor MA: Schneiderian first-rank symptoms and clinical prognostic features in schizophrenia. Arch Gen Psychiatry 26:64-67, 1972 9. Carpenter WT, Strauss JS, Muleh S: Are there pathognomonic symptoms in schizophrenia? Arch Gen Psychiatry 28:847-852, 1973 10. Abrams R, Taylor M: First-rank symptoms, severity of illness, and treatment response in schizophrenia. Compr Psychiatry 14:353-355, 1973 II. Carpenter WT, Strauss JS: Cross-cultural evaluation of Schneider’s first-rank symptoms of schizophrenia: A report from the international pilot study of schizophrenia. Am J Psychiatry 131:682-687, 1974 12. Wing J, Nixon J: Discriminating symptoms in schizophrenia. Arch Gen Psychiatry 32:853-859, 1975 13. Koehler K, Guth W, Grimm G: First-rank symptoms of schizophrenia in Schneider-oriented German centers. Arch Gen Psychiatry 34:8 10-8 13, 1977 14. Zarrouk EA: The usefullness of first-rank symptoms in the diagnosis of schizophrenia in a Saudi Arabian population. Br J Psychiatry 132:571-573, 1978 15. Bland RC: Diagnosis of schizophrenia. Can Psychiatr Assoc J 23:291-296, 1978
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16. Gharagozlou H, Behin MT: Diagnostic evaluation of Schneider first rank symptoms of schizophrenia among three groups of Iranians. Compr Psychiatry 20~242-245, 1979 17. Lewine R, Renders R, Kirchhofer M, et al: The empirical heterogeneity of first rank symptoms in schizophrenia. Br J Psychiatry 140:498-502, 1982 18. Ndetei DM, Singh A: Schneider’s first rank symptoms of schizophrenia in Kenyan patients. Acta Psychiatr Stand 67:148-153, 1983 19. Gureje 0, Bamgboye EA: A study of Schneider’s first-rank symptoms of schizophrenia in Nigerian patients. Br J Psychiatry 150:867-869,1987 20. Hoenig J: Schneider’s first rank symptoms and the tabulators. Compr Psychiatry 25:77-87, 1984 21. Chandrasena R: Schneider’s first rank symptoms: A review. Psychiatr J U Ottawa 8:86-95, 1983 22. Mellor CS: The present status of first-rank symptoms. Br J Psychiatry 140:423-424, 1982 23. Andreasen NC, Akiskal HS: The specificity of Bleulerian and Schneiderian symptoms: A critical reevaluation. Psychiatr Clin North Am 6:41-54, 1983 24. Nasrallah HA: The unintegrated right cerebral hemisphereic consciousness as alien intruder: A possible mechanism for Schneiderian delusions in schizophrenia. Compr Psychiatry 26:273-282,1985 25. Rosenbaum M: The role of the term schizophrenia in the decline of diagnoses of multiple personality. Arch Gen Psychiatry 37:1383-1385, 1980 26. Bliss EL: Multiple personalities. A report of 14 cases with implications for schizophrenia and hysteria. Arch Gen Psychiatry 37:1388-1397, 1980 27. Coons P: The prevalence of multiple personality disorder. Newsletter Int Sot Study Mult Person Dissoc 4:6-7, 1986 28. Ryan L, Ross CA, Anderson G, et al: Dissociation in adolescents and college students. Dissociation (in press) 29. Bliss EL: Multiple Personality, Allied Disorders, and Hypnosis. New York: Oxford University Press, 1986
and Geri Anderson We report structured interview data from a series of 102 cases of multiple personality disorder (MPD) diagnosed in four centers. Schneiderian first-rank symptoms of schizophrenia were equally common in all four centers. The average MPD patient had experienced 6.4 Schneiderian symptoms. When these 102 cases are combined with two previously reported series of MPD cases, an average of 4.9 Schneiderian symptoms in 368 cases of MPD is noted. This compares with an average of 1.3 symptoms acknowledged by 1,739 schizophrenics in 10 published series. Schneiderian symptoms are more characteristic of MPD than of schizophrenia. 0 1990 by W. 8. Saunders Company.
CHNEIDERIAN FIRST-RANK SYMPTOMS of schizophrenia are common in multiple personality disorder (MPD).‘*2 They differentiate MPD from eating disorders and panic disorder3 and from complex partial seizure disorder.4 In the only study comparing MPD patients with schizophrenics, however, there was no significant difference between the number of Schneiderian symptoms reported by 20 MPD patients and the number reported by 20 schizophrenics on structured interview.3 In a series of 236 cases of MPD reported to them by 203 clinicians throughout North America, Ross et al.’ observed an average of 4.5 Schneiderian symptoms of schizophrenia per patient. In a series of 30 cases, Kluft’ reported an average of 3.6 Schneiderian symptoms per patient. This report compares the frequency of Schneiderian symptoms in two large series of MPD patients to determine whether they are consistent across series. The frequency of Schneiderian symptoms in MPD is then compared with that in schizophrenia.
S
METHOD
Subjects Subjects in the first series are 236 cases of MPD reported to us by 203 clinicians throughout North America who jointly had seen 1,807 patients with MPD. Subjects in the second series are 102 patients with MPD from four centers, Winnipeg (N = 50), Utah (N = 20), California (N = 17), and Ottawa (N = 15). These subjects received their clinical diagnoses from a psychiatrist and/or research nurse in Winnipeg, from a psychologist in Utah, from an M.A. psychological assistant or a Ph.D. psychologist in California, and from a psychiatrist in Ottawa. Of the 50 patients reported from Winnipeg, four were assessed clinically only by the research nurse, who has extensive experience with both MPD and schizophrenia, and 46 were assessed by the psychiatrist.
From the Department of Psychiatry, University of Manitoba; Canyon Springs Hospital. Cathedral City. CA: Heuler, Reagor and Associates, Orange, CA; the Department of Psychiatry, University of Ottawa. Canada; and St. Boniface Hospital, Winnipeg, Manitoba, Canada.
Address reprint requests to Colin A. Ross, M.D., Department of Psychiatry, St. Bonifnce Hospital 409 Tache Ave., Winnipeg, Manitoba, R2H 2A6 Canada. 0 1990 by W.B. Saunders Company. 0010-440X/90/31 02-0005S03.00/0
Comprehensive Psychiatry, Vol. 3 1, No. 2 (March/April),
1990: pp 1 1 1- 7 18
711
112
ROSS ET AL
Procedure The first series of 236 cases was gathered by mailing a 36-item questionnaire on MPD to 1,729 members of the Canadian Psychiatric Association and to 5 15 members of the International Society for the Study of Multiple Personality and Dissociation. Each respondent was asked to complete the questionnaire on a recent case of MPD he had seen, or to indicate that he had not made a diagnosis of MPD. The questionnaire inquired about diagnostic criteria for MPD and a range of associated features. The second series was gathered by completing the Dissociative Disorders Interview Schedule (DDIS) on patients with a clinical diagnosis of MPD in each of the four centers. The DDIS is a 131-item structured interview which takes 30 to 45 minutes to administer for most patients. It has an interrater reliability of 0.68, good validity, and a sensitivity of 90% and specificity of 100% for the diagnosis of MPD.6 In Winnipeg, subjects were the first 50 patients with MPD diagnosed in the Dissociative Disorders Clinic at that center, and almost all completed the DDIS at the time of initial assessment. The procedure in Winnipeg was for the research nurse to complete the DDIS before clinical assessment was made. In Utah, subjects were interviewed consecutively in conjunction with a Ph.D. thesis study of MPD in which they agreed to participate as subjects. In California, subjects were interviewed consecutively as they presented for clinical assessment. In Ottawa, subjects were drawn from an existing caseload, and primarily included patients in therapy. No interviewers were blind to the clinical diagnoses. No investigators at any of the centers had met patients diagnosed at other centers. No MPD subjects were included in both series. The raw DDIS data were sent to the coordinating center for the study and entered and analyzed there. Although the data in Tables I through 5 are presented as percentages for ease of understanding, all responses described consisted of dichotomous yes or no answers. Therefore, chi squares were used in the analysis; t tests were used to analyze continuous variables reported below. Significance was set at P c.05. The literature on Schneiderian symptoms in schizophrenia was reviewed,?-24and the figures in Tables 3 through 5 were tabulated based on the published reports. The overall frequency and the prevalence of Schneiderian symptoms in schizophrenia were then calculated. Because not all series of schizophrenics included information on both the prevalence and the average number of Schneiderian symptoms per patient, not all series appear in both Tables 4 and 5. For some series of schizophrenics, either the frequency or prevalence of Schneiderian symptoms could be calculated from the data presented and, if so, that information is included in this report. Because only three reports”,‘*,” gave a frequency distribution of Schneiderian symptoms in schizophrenia, only those three series are reported in Table 3.
RESULTS
The subjects in the first MPD series (N = 236) had a mean age of 30.1 years (SD. 8.0), and 87.7% were female. The subjects in the second MPD series (N = 102) had a mean age of 31.8 years (S.D. 8.3), and 90.2% were female. Subjects in the two series did not differ in age (t = 1.78, NS), or sex (x2 (1) = 1.37, NS). In the first series, 37.0% of the subjects were married, 37.4% single, 23.4% separated or divorced, and 1.7% widowed and had a mean of 1.2 children (S.D. 1.4). Of the subjects in the second series 3 1.4% were married, 49.0% were single, 18.6% were separated or divorced, and 1.O% was widowed; the subjects had a mean of 1.O children (S.D. 1.4). Subjects in the two series did not differ in number of children (t = 1.21,NS). As shown in Table 1, 40.8% of subjects in the first series had received a previous diagnosis of schizophrenia, as compared with 25.6% in the second (x2 (1) = 7.12, P -C .008). Of the subjects in the first series, 54.5% had been prescribed an antipsychotic, as compared with 57.0% in the second (x2 (1) = 0.32, NS). Of the subjects in the first series, 12.1% had received electroconvulsive shock therapy (ECT) as compared with 16.7% in the second (x2 (1) = 1.16, NS).
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MULTIPLE PERSONALITY AND SCHIZOPHRENIA
Table 1. Frequency of a Previous Diagnosis of Schizophrenia and Treatment Neuroleptics and ECT in Two Series of MPD Patients
With
Series 1 (%I (N = 236)
Series 2 (%I (N = 102)
P
40.8
26.5
.008
54.5 12.1
57.0 16.7
NS NS
Previous diagnosis of schizophrenia Treatment with antipsychotic medication Treatment with ECT
Abbreviation: ECT, electroconvulsive shock therapy; NS, not significant.
The frequencies of the 11 Schneiderian symptoms in the two series are shown in Table 2. Statistical information for each of these comparisons is as follows: voices commenting (x2 (1) = 5.44, P < .02), voices arguing (x2 (1) = 1.87, NS); thoughts ascribed to others (x2 (1) = 26.41, P < .OOOOl), made feelings (x2 (1) = 22.69, P < .OOOOl),made acts (x2 (1) = 11.35, P < .OOOl),audible thoughts (x2 (1) = 6.38, P < .02), made impulses (x2 (1) = 3.69, NS), delusions (x2 (1) = 2.48, NS), thought withdrawal (x2 (1) = 6.03, P < .02), external influences (x2 (1) = 2.77, NS), and thought broadcasting (x2 (1) = 15.34, P < .OOOl). The average number of Schneiderian symptoms per patient was 4.5 (S.D. 3.3) in the first series and 6.4 (S.D. 7.3) in the second (t = 3.30, P < .Ol). As shown in Table 3,80.1% of subjects in the first series and 99.0% of subjects in the second had experienced one or more Schneiderian symptoms. Of the 102 subjects in the second series, 90.2% had experienced three or more Schneiderian symptoms. In another section of the DDIS dealing with secondary features of MPD, subjects are asked if they ever hear voices: Of the 89 subjects (87.3%) who said they did, 84 (94.4% of those hearing voices) said that they came from inside the head. There were no significant differences between MPD subjects at the four centers in the second series (N = 102) on any of the data in this report (P < .05). The frequency distribution of Schneiderian symptoms in 102 MPD patients and three series of schizophrenics is shown in Table 4. Fifty-four (52.9%) of the MPD patients, but only 16 (4.4%) of the schizophrenics, had experienced more than six Schneiderian symptoms. Table 2. Frequency
of Schneiderian First-Rank Symptoms Series of MPD Patients
Symptom Voices commenting Voices arguing Thoughts ascribed to others Made feelings Made acts Audible thoughts Made impulses Delusions Thought withdrawal External influences Thought broadcasting Abbreviation: NS, not significant.
Series 1 (96) (N = 236) 66.1 71.7 36.9 36.2 43.5 45.6 46.3 45.0 29.2 44.7 13.0
of Schizophrenia
Series 2 (%I (N = 102) 81.4 78.4 67.6 64.7 63.7 60.8 57.8 53.9 43.1 35.3 31.4
in Two
P .02 NS .00001 .00001 .0008 .02 NS NS .02 NS .OOOl
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ROSS ET AL
Table 3. Prevalence
of Schneiderian Symptoms in 12 Series of Schizophrenics Series of MPD Patients Percentage of Subjects With One or More Symptoms
Reference Schizophrenia 7 (N = 166) 8 (N = 34) 9 (N = 103) 10 (N = 71) 11 (N = 811) 12(N = 810) 13 (N = 210) 14 (N = 92) 15 (N = 50) 16 (N = 100) 18 (N = 51) 19 (N = 55) Total (N = 2,576) MPD 1 (N = 30) 5 (N = 236) Present study (N = Total (N = 368)
and Three
71.7 64.7 51.5 33.8 57.5 51.9 32.9 56.5 88.0 82.0 72.5 73.2 55.5 100.0 80.1 99.0 87.0
102)
The average number of Schneiderian symptoms per patient in 10 series of schizophrenics and three series of MPD patients are shown in Table 5. The prevalence of Schneiderian symptoms in 12 series of schizophrenics and three series of MPD patients are shown in Table 3. DISCUSSION
The findings from two large series confirm that Schneiderian symptoms are common in MPD. Voices commenting and voices arguing are the two most common Table 4. Frequency
Distribution of Schneiderian Symptoms and 361 Schizophrenics
Schizophrenia
MPD
No. of Symptoms Positive 0 1
2 3 4 5 6 7 8 9 10 11
Present Study
Koehler et al.
N
(N = 210) N
1 3 6 9 11 8 10 16 11 11 10 6
141 27 20 11 7 2 2 0 0 0 0 0
(N =
102)
in 102 MPD Patients
Gharagozlou and Behin
Ndetei and Singh
(N = N
(N = 51) N
18 9 14 13 12 15 13 6 0 0 0 0
14 11 3 4 6 3 1 3 4 0 1 2
100)
.
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MULTIPLE PERSONALITY AND SCHIZOPHRENIA
Table 5. Average No. of Schneiderian Symptoms Per Patient in 10 Series of Schizophrenics and Three Series of MPD Patients Average No. of Symptoms
Reference Schizophrenia 7 (N = 166) 9 (N = 103) 11 (N = 811) 13 (N = 210) 14 (N = 92) 15 (N = 50) 16 (N = 100) 17 (N = 100) 18 (N = 51) 19 (N = 56) Total (N = 1,739) MPD 1 (N = 30) 5 (N = 236) Present study (N = Total (N = 368)
1.3 1.4 1.0 0.7 1.7 1.8 1.6 1.7 3.1 2.4 1.3
102)
3.6 4.5 6.4 4.9
symptoms in both series. This is consistent with the clinical understanding of MPD, in which the voices are recognized to be those of alter personalities.’ In the series of 102 MPD cases, 94.4% of subjects hearing voices said that they came from inside the head. This is believed to be a feature of MPD auditory hallucinations which differentiates them from those of schizophrenia. Schizophrenic voices tend to come from outside the head. The data in the three MPD series were gathered in different ways. One series (N = 236) was generated by having 203 respondents complete a questionnaire mailed to them. The second series (N = 30) was generated by careful clinical interview and chart review by a single clinician reviewing his own caseload. The third series (N = 102) was generated by having professionals at four centers with a specialty interest in MPD administer a structured interview to their patients. In Utah the patients were subjects for a Ph.D. thesis, in Winnipeg and California they were interviewed consecutively at the time of initial assessment, and in Ottawa most patients were in treatment. Despite this variation in the timing and purpose of the structured interviews in the third series, there were no differences between centers on the demographic characteristics, or the mean number of Schneiderian symptoms endorsed. The findings indicate that Schneiderian symptoms are reported in a consistent fashion by MPD patients throughout North America and that their acknowledgment of these symptoms does not differ whether they are research subjects, treatment cases, or interviewed at the time of assessment for MPD. The degree of variation between the two large MPD series on individual Schneiderian symptoms is similar to that observed when different series of schizophrenics are compared.20~2’ We do not believe that this degree of variability has any conceptual importance. The DDIS does not result in an indiscriminate acknowledgment of Schneiderian symptoms by clinical subjects. The average number of Schneiderian symptoms acknowledged on the DDIS by patients with panic disorder is 0.3,3 with eating
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disorders 1.7,3 with complex partial seizures 0.5,4 and with other neurological disorders 0.3.4 One cannot argue that the rate of Schneiderian symptoms in MPD is an artifact of the DDIS, and it was used in only one of the three MPD series described in Tables 1 through 5. When the three available series of MPD patients for whom Schneiderian symptoms have been tabulated are compared with published series of schizophrenics, it is clear that MPD patients consistently experience more of these symptoms than do schizophrenics. Indeed, 52.9% of MPD patients but only 4.4% of schizophrenics have experienced more than six Schneiderian symptoms. Both the average number of Schneiderian symptoms per patient and the prevalence of patients with one or more symptoms are higher in MPD than in schizophrenia: There was no overlap between the MPD and schizophrenia series on the average number of symptoms per patient and only a small amount of overlap on the prevalence. When the three series of MPD cases are totaled (N = 368), the average number of Schneiderian symptoms per patient is 4.9 compared with an average of 1.3 for 1,739 schizophrenics. This finding, together with the frequency distribution of Schneiderian symptoms described in Table 3, demonstrates that the greater the number of Schneiderian symptoms reported by a patient, the more likely the diagnosis is MPD and the less likely it is schizophrenia. We, and Kluft,’ were aware of the need to differentiate MPD from schizophrenia25*26 and carefully ruled out schizophrenia in their clinical assessments. The same is likely true of most repondents in the series of 236 cases of MPD: All cases in this series met DSM-III-R criteria for MPD. We are confident that the 368 cases of MPD are not contaminated by unrecognized cases of schizophrenia. The inverse does not hold, however. There is no evidence that any of the investigators reporting series of schizophrenics considered MPD in their clinical assessments, and none of their instruments make dissociative diagnoses. As shown in Table 1, many MPD patients have been misdiagnosed as schizophrenic and treated with neuroleptics and ECT.2 This raises the question of whether reported series of schizophrenics are contaminated by a significant number of undiagnosed MPD patients. The likelihood that this is true hinges on the prevalence of MPD, which has not been determined. According to one estimate, 6,000 patients with MPD had been diagnosed in North America by 1986. 27 The respondents reporting the series of 236 cases of MPD had jointly seen 1,807 patients. This information alone suggests that MPD is not rare. Based on our own clinical experience, preliminary screening studies in clinical and nonclinical populations,28 and our reading of the literature, we suspect that MPD has a point prevalence greater than 1 in 1,000 adults in North America. If this is true, a significant contamination of schizophrenic research series by undiagnosed MPD patients is likely to have occurred in the last two decades. The average number of Schneiderian symptoms in schizophrenia may actually be less than 1.3, if all cases of MPD are excluded. Because Schneiderian symptoms are relatively uncommon in schizophrenia, they may be specific for a subtype of schizophrenia and not for the heterogeneous group of schizophrenias as a whole. Whether schizophrenics with a large number of Schneiderian symptoms have higher rates of childhood trauma and of other dissociative symptoms than
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schizophrenics with no Schneiderian symptoms will be important to determine. There may be a dissociative subtype of schizophrenia with distinct premorbid features, onset, symptoms, treatment response, and prognosis. The present data only hint at this possibility, but systematic investigations could be conducted with the DES and DDIS. At present, any patient with Schneiderian symptoms should be assessed for a history of childhood abuse, amnesia in one or more forms, and MPD. The evidence from two large series suggests that a considerable number of patients in North America may have been given false-positive diagnoses of schizophrenia and false-negative diagnoses of MPD. Because the treatments of the two disorders differ radically, it is important to differentiate between schizophrenia and MPD carefully and systematically. This can be done using the DES, and DDIS, and/or a clinical interview which makes a specific inquiry for symptoms present in MPD and absent in schizophrenia. Preliminary evidence suggests that hypnotizability testing can also differentiate MPD from schizophrenia, with dissociative patients scoring higher.2g Tools to differentiate MPD from schizophrenia with good reliability and validity are available in the literature. Previous studies have shown that Schneiderian symptoms are not pathognomonic for schizophrenia and occur in other psychiatric disorders and in normal controls.23 The present study indicates that they are better described as first-rank symptoms of MPD than of schizophrenia. REFERENCES 1. Kluft RP: First-rank symptoms as a diagnostic clue to multiple personality disorder. Am J Psychiatry 144:293-298, 1987 2. Ross CA, Norton CR: Multiple personality patients with a past diagnosis of schizophrenia. Dissociation 1:39-42, 1988 3. Ross CA, Heber S, Anderson G, et al: Differences between multiple personality disorder and other diagnostic groups on structured interview. J Nerv Ment Dis 177:487-491, 1989 4. Ross CA, Heber S, Anderson G, et al: Differentiating multiple personality disorder and complex partial seizures. Gen Hosp Psychiatry 11:54-58,1989 5. Ross CA, Norton GR, Wozney K: Multiple personality disorder: An analysis of 236 cases. Can J Psychiatry 34:413-418, 1989 6. Ross CA, Heber S, Norton GR, et al: The dissociative disorders interview schedule: A structured interview. Dissociation (in press) 7. Mellor CS: First rank symptoms of schizophrenia. Br J Psychiatry 117:15-23, 1970 8. Taylor MA: Schneiderian first-rank symptoms and clinical prognostic features in schizophrenia. Arch Gen Psychiatry 26:64-67, 1972 9. Carpenter WT, Strauss JS, Muleh S: Are there pathognomonic symptoms in schizophrenia? Arch Gen Psychiatry 28:847-852, 1973 10. Abrams R, Taylor M: First-rank symptoms, severity of illness, and treatment response in schizophrenia. Compr Psychiatry 14:353-355, 1973 II. Carpenter WT, Strauss JS: Cross-cultural evaluation of Schneider’s first-rank symptoms of schizophrenia: A report from the international pilot study of schizophrenia. Am J Psychiatry 131:682-687, 1974 12. Wing J, Nixon J: Discriminating symptoms in schizophrenia. Arch Gen Psychiatry 32:853-859, 1975 13. Koehler K, Guth W, Grimm G: First-rank symptoms of schizophrenia in Schneider-oriented German centers. Arch Gen Psychiatry 34:8 10-8 13, 1977 14. Zarrouk EA: The usefullness of first-rank symptoms in the diagnosis of schizophrenia in a Saudi Arabian population. Br J Psychiatry 132:571-573, 1978 15. Bland RC: Diagnosis of schizophrenia. Can Psychiatr Assoc J 23:291-296, 1978
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16. Gharagozlou H, Behin MT: Diagnostic evaluation of Schneider first rank symptoms of schizophrenia among three groups of Iranians. Compr Psychiatry 20~242-245, 1979 17. Lewine R, Renders R, Kirchhofer M, et al: The empirical heterogeneity of first rank symptoms in schizophrenia. Br J Psychiatry 140:498-502, 1982 18. Ndetei DM, Singh A: Schneider’s first rank symptoms of schizophrenia in Kenyan patients. Acta Psychiatr Stand 67:148-153, 1983 19. Gureje 0, Bamgboye EA: A study of Schneider’s first-rank symptoms of schizophrenia in Nigerian patients. Br J Psychiatry 150:867-869,1987 20. Hoenig J: Schneider’s first rank symptoms and the tabulators. Compr Psychiatry 25:77-87, 1984 21. Chandrasena R: Schneider’s first rank symptoms: A review. Psychiatr J U Ottawa 8:86-95, 1983 22. Mellor CS: The present status of first-rank symptoms. Br J Psychiatry 140:423-424, 1982 23. Andreasen NC, Akiskal HS: The specificity of Bleulerian and Schneiderian symptoms: A critical reevaluation. Psychiatr Clin North Am 6:41-54, 1983 24. Nasrallah HA: The unintegrated right cerebral hemisphereic consciousness as alien intruder: A possible mechanism for Schneiderian delusions in schizophrenia. Compr Psychiatry 26:273-282,1985 25. Rosenbaum M: The role of the term schizophrenia in the decline of diagnoses of multiple personality. Arch Gen Psychiatry 37:1383-1385, 1980 26. Bliss EL: Multiple personalities. A report of 14 cases with implications for schizophrenia and hysteria. Arch Gen Psychiatry 37:1388-1397, 1980 27. Coons P: The prevalence of multiple personality disorder. Newsletter Int Sot Study Mult Person Dissoc 4:6-7, 1986 28. Ryan L, Ross CA, Anderson G, et al: Dissociation in adolescents and college students. Dissociation (in press) 29. Bliss EL: Multiple Personality, Allied Disorders, and Hypnosis. New York: Oxford University Press, 1986
