SOMATIC SYMPTOMS
IN MULTIPLE
SCLEROSIS
AND MPD
Colin A. Ross, M.D., FRCPC
Eunice Fast, B.A.
Geri Anderson, R.P.N.
Anthony Auty, B.M., B.C.H., FRCPC
Judy Todd, R.N.
Cohn A. Ross, M.D., FRCPC, is an associate professor in the
Department of Psychiatry at the University of Manitoba.
Eunice East, B.A., is a medical student. at. the University of
Manitoba.
Geri Anderson, R.P.N., is a Dissociative Disorders Nurse Clini-
cian in the Department of Psvchiauy at St. Boniface Hospital,
Winnepeg, Manitoba.
Anthony Auty, B.M., B.C.I I., FRCPC, is Director of MS Clinic
and an assistant professor in the Department of Medicine
(Neurology), University of Manitoba.
Judy Todd, R.N., is a MS Clinic Coordinator in Winnepeg,
Manitoba.
For reprints write the Deparuneut of Psvcltiatry, St. Boniface
Hospital, 409 Tactic Avenue, Winnipeg, Manitoba R211 2A6,
Canada.
This article is based on a paper presented at the Sixth Annual
International Conference on Multiple Personality/Dissocia-
tive States, Chicago, October 14, 1989.
ABSTRACT
In this report 50 subjects with multiple sclerosis are compared to 50
subjects with multiple personality disorder. The multiple sclerosis patients
endorsed an average (1 3.0 somatic symptoms on structuredinterview,
the multiple personality subjects an average of 14.5. The somatic
symptoms characteristic of neurological illness were trouble walking,
paralysis, and muscle weakness. Those characteristic of psychiatric
illness were genitourinary and gastrointestinal symptoms.
In a contemporary series of 102 cases of multiple person-
ality disorder (MPD), 60.8% met DSM-III-R criteria for soma-
tization disorder (Ross, Miller, Reagor, Bjornson, Fraser, &
Anderson, 1990). Individuals with MPD can be differentiated
from other psychiatric diagnostic groups by the frequency with
which they experience somatic symptoms (Ross, Heber, Nor-
ton, & Anderson, 1989a; Ross, Heber, Norton, & Anderson,
1989b). In MPD patients, somatic symptoms appear to be
related to childhood trauma, and, like Schneiderian symp-
toms, may be "somatic memories" of particular abuse incidents
(Kluft, 1987). The psychosomatic symptoms of MPD patients
are a recurrent theme in the dissociative literature (Coons,
1988; Putnam, 1989; Ross, 1989).
There is a concern expressed in the psychiatric and med-
ical literature that psychosomatic symptoms may he difficult to
differentiate from those ofmultiple sclerosis (MS) , especially in
the early stages of MS (Caplan & Nadelson, 1988; LaRocca,
1984; Tomsvck& Jenkins, 1987). This is partly due to the fact
that MS often strikes women aged 20 to 40. It is of note that
MPD patients in clinical series also tend to he women in this age
group (Putnam, Groff, Silberman, Barban, & Post, 1986; Ross,
Norton, & Woznev, 1989).
This study compares the somatic symptoms experienced
by MS patients with those experienced by MPD patients to
delineate any differences in somatic syrnptomatology between
MS and MPD. The study was motivated by an additional
concern which is admittedly quite speculative: since MS in-
volves patchy demyelination of the central nervous system, it is
conceivable that it could cause a failure of normal integrative
fu nctions and result in dissociative symptoms. If this were the
case, MS might provide a biomedical model of dissociation for
further study. Dissociative symptoms were also enquired about
to explore this possibility.
METHODS
Subjects
We interviewed 50 MS patients and 50 MPD patients using
the Dissociative Disorders Interview Schedule (DDIS) (Ross,
1989; Ross, Heber, Norton, Anderson, Anderson, & Barchet,
1989) and the Dissociative Experiences Scale (DES) (Bernstein
& Putnam, 1986).
The MS subjects were selected from patients attending an
MS clinic. To avoid selection bias the first 44 patients over 18
years with clinically definite MS were interviewed. Patients with
additional neurological diagnoses, such as stroke and demen-
tia, were excluded from the study. Due to difficulties with
recruitment the final six MSsubjectswere selected nonrandomly
by review of clinic files. The first 50 MPD patients assessed at our
Dissociative Disorders Clinic were inter viewed. After explana-
tion of the procedure, signed informed consent was solicited
from each patient before the interview. There were no refusals
in either the MS or MPD groups. Ethical approval had been
received from the Faculty Committee on the Use of Human
Subjects in Research at the University of Manitoba.
Instruments
The Dissociative Disorders Interview Schedule (DDIS) is a
131-item structured interview which takes 30-45 minutes to
administer. It has an overall inter-rater reliability of 0.68, a
sensitivity of 90% and a specificity of 100% for the diagnosis of
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ROSS/FAST/ANDERSON/AUTY/TODD
MPD (Ross, et al., 1989). The inter-rater reliability of the DDIS
for the DSM-1II-R diagnosis of somatization disorder is 0.69.
The Dissociative Experiences Scale is a 28-item self--report
instrument with good validity and a test-retest reliability of 0.84
(Bernstein & Putnam, 1986).
Data Analysis
Chi square analysis was used when comparing MS and
MPD patients on dichotomous variables, and the Mann-Whit-
ney U test when comparing them on continuous variables.
In comparing the MS and MPD groups on the 35 DSM-II1-
R symptoms of somatization disorder, the Bonterroni proce-
dure for multiple comparisons was used to avoid Type 1 errors
(Grove & Andreasen, 1982). After application of the Ronfer-
roni procedure the significance level for these items was
p < .002. Symptoms experienced by MS patients that can be
attributed to their disease are normally scored negative by
DSM-ill-R criteria. However, for the purpose of differentiating
between types of symptoms experienced by MS and MPD
patients we included symptoms attributed to MS as positive.
RESULTS
Demographic Characteristicsof Subjects
Of the 50 MS subjects, 19 were male and 31 were female,
with a mean age of 44.9 (S.D. 9.8) years (age range: 32-71).
Twenty-nine subjects were married, 13 single, 12 separated or
divorced, and 3 widowed. Only 7 subjects were employed.
Six of the MPD patients were ale and 44 female which is
significandydiflerentfrom MS patients (X~(1) = 7.68, p < .006).
MPD patients had a mean age of 30.2 (S.D. 9.2) years, which is
significantly different from the MS patients (U(98) = 2194.0,
p < .00001). Nineteen MPD patients were employed, 13 mar-
ried, 23 single, 13 separated or divorced, and one widowed.
Neurological Status of Multiple SclerosisPatients
In the MS patients, the mean age at onset of MS was 32.7
(S.D. 9.4) years. The mean duration ofillnesswas 12.3 (S.D. 7.7)
years. Five of the MS patients did not have a progressive illness
at the time of the study. Of the remaining subjects, 24 had a
relapsing-progressive pattern and 21 a chronic progressive
pattern. In thirty of these subjects the duration of the progressive
phase of their illness was over two years in duration.
According to clinical assessment by a neurologist, 30 sub-
jects had involvement of the brain stem, 48 the spinal cord, 24
the cerebellum, 5 the cerebrum, and 22 the optic ner v
the subjects had involvement of only one area, 20 of two areas,
14 of three areas, 9 of four areas, and one of five. The mean
number of areas involved was 2.6 (S.D. 1.0).
No MPD subjects had a diagnosis of MS.
Abuse Histories
Five MS subjects suffered sexual abuse during childhood
with a mean duration of 0.8 (S.D. 1.8) years. Two of these also
experienced physical abuse along with two additional subjects.
The mean duration of physical abuse experienced by the four
subjects was 7.0 (S.D. 5.5) years. For MPD subjects, 84% were
sexually abused with a mean duration of 10.0 (S.D. 8.6) years
and 78% were physically abused with a mean duration of 13.0
(S.D. 6.9) years. The two groups differed on the percentage
of subjects experiencing physical , (X 2 (1) = 52.03, p < .0001)
and sexual (X'(1) = 47.16, p < .00001) abuse. The duration of
physical abuse did not differ between the two groups, while the
duration of sexual abuse did (U(40) = 20.5, p < .006) .
Somatic Symptoms
Only one MS subject had a diagnosis of somatization
disorder compared with 13 MPD subjects (V(1) =10.1, p<.002) .
Using I)SM-HI-R criteria, MS patients scored significantly lower
than MPD patients (U(98) = 202.5, p < .00001) on average
number of somatic symptoms reported. The MS subjects re-
ported an average 4 3.0 (S.D. 3.8) somatic symptoms, while the
MPD subjects reported an average of 14.5 (S.D. 7.5) .
In comparing each somatic symptom, using our analysis ii
which symptoms attributed to MS are positive, there is a
significant difference in certain groups of symptoms between
MS and MPD patients (see Table 1) . After using the Bon ferroni
procedure, MS patients experience trouble walking and paral-
ysis or muscle weakness significantly more often. Symptoms
experienced more often by MPD patients are abdominal pain,
nausea, voit.ing, bloating, intolerance offoods, pain in the
genitals, pain during intercourse, palpitations, chest pain, and
amnesia. The remaining 23 symptoms do not difleren tiate the
two groups significantly.
Dissociation and Related Symptoms
Previous research has shown that Schneiderian symptoms,
ESP experiences, borderline personality disorder criteria, so-
matic symptoms, and secondary feann res of MPD are part of a
large cluster of symptoms common in patients with abuse
histories and dissociative disorders (Ross, 1989; Ross, et al.,
1990). MS subjects scored significantly lower on all these
categories compared with MPD subjects.
The MPD subjects reported an average of 6.3 (S.D. 2.9)
Schneiderian symptoms and the MS patients an average of 1.0
(S.I). 2.1), (U(98) = 162.0, p < .00001). The MPD subjects
reported an average of 5.4 (S.D. 3.7) supernatural/extrasenso-
r-experiences and the MS subjects an average of 1.0(S.D. 1.6),
(U(98) = 281.0, p <.00001). The MPD subjects reported an
average of 5.7 (S.D. 2.2) positive borderline personality disor-
der criteria and the MS subjects an average of 0.9(S.D. 1.5),
(U(98) = 139.5, p < .00001). The MPD subjects reported an
average of 9.1 (S.D. 3.6) secondary features of MPD and the MS
subjects an average of 0.8 (S.D. 1.4), (U (98) =41.0,p<.0001).
The MS subjects scored an average of 6.4 (S.D. 10.3) on the
DES, which is in the normal range, compared with 36.9 (S.D.
19.7) for MPD subjects (U(98) = 174.0, p < .00001) .
DISCUSSION
In comparing MPD and MS patients, our study clearly
indicates that MS patients as a group are not dissociative. They
score in the normal range on the DES and do not endorse the
symptom clusters characteristic of MPD on the DDIS. Dernyeli-
nation of the central nervous system does not provide a bio-
medical model ofdissociation, although individual MS patients
may experience dissociative symptoms. The fact that the MPD
subjects were younger and more predominantly female does
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SOMATIC SYMPTOMS IN MULTIPLE SCLEROSIS AND MPD
TABLE 1
Somatic Symptoms in Multiple Sclerosis and Multiple Personality Disorder
Multiple
Personality
Multiple
Sclerosis
Disorder (N=501
(N=50)
Number of
Symptom Subjects Positive p value
Abdominal pain 36 6 .00001
Nausea 35 6 .00001
Dizziness 35 19 N.S.
Palpitations 34 8 .00001
Amnesia 34 5 .00001
Sexual indifference 34 23 N.S.
Intolerance of foods 26 5 .00001
Vomiting 26 3 .00001
Bloating 26 9 .0006
Back pain 25 22 N.S.
Shortness of breath 25 12 N.S.
Irregular periods '25 13 N.S.
Painful menstruation 24 8 N.S.
Chest pain 24 S .001
joint pain 24 17 N.S.
Blurred vision 23 27 N.S.
Excessive menst rual bleeding 23 9 N.S.
Pain during intercourse 21 4 .0002
Urinary retention 20 27 N.S.
Diarrhea 19 7 N.S.
Pain in extremities 19 16 N.S.
Paralysis or muscle weakness 19 43 .00001
Double vision 18 23 N.S.
Other pain 17 6 N.S.
Pain during urination 15 3 N.S.
Difficulty swallowing 15 17 N.S.
Fainting 15 6 N.S.
Pain in genitals 14 1 .0007
Trouble walking 12 47 .00001
Seizures/convulsions 11 2 N.S.
Vomiting during pregnancy 11 4 N.S.
Loss of voice 10 8 N.S.
Deafness 8 3 N.S.
Blindness 2 12 N.S.
Impotence 1 7 N.S.
* after ap plication of the Bonferroni procedure the significance level for these items is
p <.002* the difference between groups on painful menstruation did not reach significance because of missing data for that item
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ROSS/FAST/ANDERSON/AUTY/TODD
not call this conclusion into question: if MS provided a biomed-
ical model of dissociation, dissociative symptoms would be-
come more apparent as the disease progressed with age.
MS is the. second disorder ruled out as a biomedical model
of dissociation. Temporal lobe epilepsy has also failed to
provide a model organic dissociative syndrome (Dcvinsky,
Putnam, Graf man, Bromfield, & Theodore, 1989; Loewenstein
& Putnam, 1988; Putnam, 1986; Putnam, 1989; Ross, 1989;
Ross, et al., 1989).
The somatic svinptomatology of MS patients, although
historically often confused with somatization disorder, has a
notably different cluster when compared with somatoform
findings in MPD patients. Nearly all of the MS patients had at
one time experienced trouble walking (94%) and paralysis or
muscle weakness (86%). The cluster of symptoms that was
elevated significantly in MPD patients consists mainly ofgastroi-
ntestinal and genitourinary svmptomatology.
Morrison (1989) found that 55% of 60 patients with
primary diagnoses of somatization disorder had childhood
sexual abuse histories, and three had MPD. MPD patients are
also abuse survivors and have many somatic symptoms. We
suspect that assessment of Morrison' s subjects with the DES and
DDIS might have yielded more dissociative diagnoses and
symptomatology. A recent review of current theories of soma-
tization disorder (Kellner, 1990) did not mention childhood
abuse, however. The relationship between s omatization and
sexual abuse seems not to have been accepted by many clini-
cians.
A limitation of the current study is that MPD patients may
not be representative of most individuals with numerous psy-
chosomatic symptoms. It would be of interest to determine the
differences in symptom patterns between women with primary
diagnoses of somatization disorder who have been sexually
abused as children and those who have not, using the DES and
DDIS. Such a study might further support the relationship
between childhood sexual abuse and somatic complaints in the
genitourinary and gastrointestinal systems.
As Ruegg (1990) has pointed out, the relationship between
somatic symptoms and childhood sexual abuse raises questions
about the transmission of somatization disorder from one
generation to the next. In some families females tend to have
somatization disorder and males antisocial personality disorder.
Perhaps what is really "transmitted" in these families is child
abuse. Abused males develop antisocial personality and asser-
tively mate with abused females, who have developed somatiza-
tion disorder, and vice versa. The children of these unions are
at risk for child abuse, thus perpetuating the cycle. Such a
pattern of transmission would apply to certain somatic symp-
toms but not to those characteristic of MS, which are caused by
demyelination of the nervous system. 
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