Psychological Reports, 1990, 66, 831-834. @ Psychological Reports 1990
ACCURACY O F THE MMPI IN IDENTIFYING MULTIPLE PERSONALITY DISORDER ' PHILIP M. COONS
Indiana Universily School of Medicine, Larue D. Carter Memorial Hospital
CATHERINE G. F I N E Eugenia Hospital
Summary.-A number of previous studies have delineated Minnesota Multiphasic Personality Inventory (MMPI) characteristics in patients with multiple personality. To test the accuracy of the MMPI in identifying such patients, the authors blindly rated 63 MMPIs as being e~thermultiple personality or not. The over-all hit rate for the entire sample was 71 4%, with a 68% hit rate for correctly identified patients with multiple personalily These hit rates compare favorably with the hit rates in similar studies of other psychiatric disorders and further demonstrate the clinical usefulness of the MMPI in the diagnosis of multiple personality.
Recent studies have delineated MMPI characteristics of patients with multiple personality (Solomon, 1983; Bliss, 1984; Coons & Sterne, 1986). These MMPI features include (a) high F and Sc scales, (b) technically invalid profiles in about one-third of cases, (c) numerous critical items, (d) critical items 156 and 251 inIcating Issociation, (e) a polysymptomatic picture simulating borderline personality disorder profiles, ( f ) obvious scores generally much higher than subtle scores, (g) lack of blatant psychosis with the exception of auditory hallucinations which are the "inner voices" of the other ego states, and (h) infrequently elevated Hs scales. Coons and Sterne (1984) found that the mean T scores for the F and Sc scales were 82.3 and 90.5, respectively, while the mean HI T score was 69.9. The mean number of clinical scales elevated above T-70 was six. The mean number of critical items (Grayson, 1951) checked was 14.6. The obvious scores of clinical Scales 2, 3, 4, 6, and 9 were greater than the subtle scores 86% of the time, with a mean difference of 28.1. Other common MMPI features seen in multiple personality from our clinical experience include low ego strength, high familial discord, and critical items connoting sexual dysfunction, particularly if there has been an history of childhood sexual abuse.
METHOD To test the accuracy of using the MMPI in identifying patients with multiple personality, the authors blindly rated 63 MMPIs (566-item group form) as being either multiple personality or not. These MMPIs were coded by number and listed only the patient's age and sex for scoring purposes. The protocols were from 63 adult psychiatric patients usually given as part of 'Requests for reprints should be addressed to Philip M. Coons, M.D., Larue D. Carter Memorial Hospital, 1315 West 10th St., Indianapolis, IN 46202.
P. M. COONS
C. G. FINE
their initial psychiatric assessment. In the case of the multiple personality patients, the MMPIs were given to the presenting persons, often before the diagnosis of multiple personality was even known or suspected. DSM-111-R (American Psychiatric Association, 1987) criteria were used to make the diagnoses. To make it difficult for the raters to differentiate between multiple personality and others, the MMPIs from patients with other diagnoses included those with DSM-111-R diagnoses easily confused with or often coexistent with multiple personality such as schizophrenia (Coons, 1984; Kluft, 1987), borderline personality disorder (Solomon & Solomon, 1982; Horevitz & Braun, 1984), or affective disorders, particularly depression (Coons, 1984; Putnam, Guroff, Silberman, Barban, & Post, 1986). RESULTS The 63 patients were 25 patients with diagnoses of multiple personality and 38 patients with orher diagnoses, including 11 with borderline personality disorder, 11 with depressive disorders, 5 with schizophrenia, 5 with other person&ty disorder diagnoses, and 6 with various other diagnoses. There were 55 women and 8 men, one of whom had multiple personality. The mean ages for the multiple personality group, the group with other diagnoses, and the entire sample were 33.4 yr., 31.0 yc, and 32.0 yr., respectively. The sample included 35 patients from Larue D. Carter Memorial Hospital, a state psychiatric facility, and 28 patients from the private practice of C.F. and her associates in the Philadelphia area. Both inpatients and outpatients were represented. The over-all hit rate for the entire sample was 71.4%, with a 68% (17125) hit rate for patients with multiple personality. The over-all hit rate for C.F. was 65.6% (23/35), with a 71.4% (10114) hit rate for multiple personality. The over-all hit rate for P.C. was 78.5% (22128) with a 63.6% (7111) hit rate for multiple personality. Although the false negative rate for C.F. and P C . were similar (28.5% and 36.3%, respectively), the false positive hit rates were quite different for C.F. and PC. (44.4% and 22.2%, respectively). Reasons for this difference were not obvious. DISCUSSION A number of early studies of MMPI characteristics in patients with multiple personality included MMPI profiles which varied markedly among personality states for a given individual (Ludwig, Brandsma, Wilbur, Benfeldt, & Jameson, 1972; DeHerrera, 1976; Brassfield, 1980; Confer & Ables, 1983). Unlike the present study, the MMPI was given some time after the diagnosis of multiple personality had been made when dissociation was often marked and, in at least two instances, in extremely artificial test situations where hypnosis was employed to keep the patient in a given personality state (Ludwig, et al., 1972; DeHerrera, 1976). These early srudies may have kept
MMPI AND MULTIPLE PERSONALITY
some clinicians from employing the MMPI with multiple-personality patients. The 71% hit rate in this study compares very favorably with the hit rates in other studies including a 37 to 65% hit rate for schizophrenia (Winters, 1981; Rogers, 1982), a 64 to 78% hit rate for borderline personality (Hurt, Clarkin, Francis, Abrams, & Hunt, 1985; Gustin, Goodpaster, Sajadi, Pitts, LaBasse, & Snyder, 1983), a 67 to 82% high rate for affective disorders (Rogers, Wasyliw, & Dolmetsch, 1982; Post, Clopton, Keefer, Rosenberg, Blyth, & Stein, 1986), and a 57 to 82% hit rate for posttraumatic stress disorders (Keane, Malloy, & Fairbank, 1984; Gayton, Burchstead, & Matthews, 1986). Although the MMPI findings in multiple personality and other psychiatric disorders are certainly not pathognomonic for any of these conditions, the MMPI still has a certain diagnostic utdity. In the case of multiple personality, the MMPI is but one of a number of clinical tools such as the psychiatric history and mental status examination which provide diagnostic clues. In conclusion, this study provides further evidence of the usefulness of the MMPI in the diagnosis of multiple personahty. REFERENCES AMERICANPSYCHIATRICASSOCIATION. (1987) Diagnostic and statistical manual of mental disorders. (3rd ed., rev.) Washngton, DC: American Psychiatric Press. Buss, E. L. (1984) A s mptom profile of patients with multiple personality including MMPI S Mental Diseare, 172, 197-202. results. Journal O ~ N ~ W O U and BRASSFIELD, P. A. (1980) A discriminative study of the dissociative slntes ofa multiple personality. Ann Arbor, MI: University Microfilms International. CONFER,W. N., & ABLES, B. S. (1983) Multiple personality: etiology, diagnosis, and treatment. New York: Human Sciences Press. COONS,P. M. (1984) The lfferential diagnosis of multiple personality lsorder: a comprehensive review. Psychiatric Clinics of North America, 7, 5 1-67. COONS,I? M., & STERNE,A. L. (1986) Initial and followup psychological testing on a group of patients with multiple personality disorder. Psychological Reports, 58, 43-49. DEHERRERA,L. J. (1976) Case study of a multiple personality. Ann Arbor, MI: University Microfilms International. GAYTON, W. F., BURCHSTEAD, G . W., & ~ ~ I T H EG W . R.S(1986) , An investigation of the utility of an MMPI posttraumatic stress disorder scale. Journal of Consulting Psychology, 42, 916-917. GRAYSON, H. M. (1951) A psychological admission testing program and manual. Los Angeles, CA: Veterans' Administration Center Neuropsychiatric Hospital. GUSTON,Q. L., GOODPASTER, W. A,, SAJADI,C., PIITS, W. M., LABASSE, D. L., & SNYDER,S. (1983) MMPI characteristics of the DSM-I11 borderline personality disorder. Journal of Personality Assessment, 47, 50-59. HOREVITZ,R. F'., & BRAUN,B. G. (1984) Are multiple personalities borderline? An analysis of 33 cases. Psychiatric Clinics of North America, 7, 69-87. HURT, S. W., CLARKIN, J. F., FRANCIS,A,, ABRAMS,R., & HUNT,H . (1985) Discriminant validity of the MMPI for borderline personality disorder. Journal of Personality Assessment, 49, 56-61. KEANE,T. M., W L O Y ,F'. F., & FAIRBANK, J. A. (1984) Empirical development of an MMPI subscale for the assessment of combat-related posttraumatic stress disorder. Journal of Consulting and Clinical Psychology, 52, 888-891. K r m , R. P. (1987) First-rank symptoms as a diagnostic clue to multiple personality disorder. American Journal of Psychiatry, 144, 293-298.
P. M. COONS & C. G. FINE
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Accepted March 28, 1990.