THE DISSOCIATIVE
EXPERIENCES SCALE:
FURTHER REPLICATION
AND VALIDATION
Edward J. Frischholz, Ph.D.,
Bennett G. Braun, M.D.,
Roberta G. Sachs, Ph.D.,
Laura Hopkins, Denise M. Shaeffer,
Jennifer Lewis, Frank Leavitt, Ph.D.,
James N. Pasquotto, MA.
and David IL Schwartz
Edward J. Frischholz, Ph.D., is Director of Research at the
Dissociative Disorders Program, Rush-I'resbvterian-St. Luke's
Medical Center and is an adjunct professor of psychology at
the University of Illinois at Chicago. Bennett G. Braun, M.D.,
is Director of the Dissociative Disorders Program, Rush-
Presbyterian-St. Luke's Medical Center, Dissociative Disor-
ders Inpatient Unit, Rush North Shore Medical Center, and
is an adjunct professor of psychology at the University of
Illinois at Chicago. Roberta G. Sachs, Ph.D., is the Director
of Training at the Dissociative Disorders Inpatient Unit,
Rush North Shore Medical (:enter. Laura Hopkins, Denise
M. Shaeffer, and Jennifer Lewis are affiliated with the Disso-
ciative Disorders Program, Rush-Presbyterian-St. Luke 's
Medical Center, and University of Illinois at Chicago. Frank
Leavitt, Ph.D., is at the Department of Psychology Rush-
Presbyterian-St. Luke's Medical Center, Chicago, Illinois.
James N. Pasquouo, M.A., is associated with the Illinois
University Affiliated Program in Developmental Disabilities,
University of lllinois at Chicago. David R. Schwartz, B.A., is
associated with the Dissociative Disorders Inpatient Unit,
Rush North Shore Medical Center, Skokie, Illinois.
For reprints write Edward J. Frischholz, Ph.D., Director of
Research, Dissociative Disorders Program, Rush-North Shore
Medical Center, 9600 Gross Point Road, Skokie, Illinois
60076.
ABSTRACT
The purpose of the present study was to provide further evidence in
support of the validity cftheDissociative Experiences ,Scale /DES] as
a reliable measure of dissociative psychopathology. The DES was
administered to 259 college students, .3 .3 patients with multiple
personality disorder (MPD), and 29 patients with a dissociative
disorde r not otherwise specified (DDNOS)_ The inter-rater reliability
for the DES scoring procedure was cxcelh at (coefficient of absolute
agreement=. 96; coefficient of relatives rr,z;;nt =. 99). The lest retest
reliability of DES scores (within approximately one month) was also
excellent (coefficient of absolute agreement =. 93; coefficient of relative
agreement=. 96) and suggests that DES total scores are temporally
stable and similar in. absolute value across testings. Finally, the
internal consistency of DES scores was also very high (alpha fur
students=. 93; alpha for MPD patients =. 94; alpha for DDNOS
patients=. 94; alpha for the combined total .sample=. 95). Bath MPD
(mean DES score =55.0) and DDNOS patients (mean DES score =40.8)
earned significantly higherDES scores than students (mean DES score
=23.8). In addition, MPD patients earned significantly higher DES
scores than DDNOS patients. The results of the present study also
suggest that a DES cutoff scare of 45 to 55 maximizes the probability
of correctly classifying students from dissociative disorder patients
(87%) while minimizing the rates of false positive (2 to 6 %) and
false negative errors (7 to 11 `~ )..Su ,ggestions for/111Mo- validation
research are also made.
The Dissociative Experiences Scale (DES: Bernstein &
Putnam, 1986) is a brief, 28 item, self-report inventory of
both normal and abnormal experiences. The DES was de-
veloped "to offer a means of reliably measuring dissociation
in normal and clinical populations" (Bernstein & Putnam,
1986, p.727). Preliminary psychometric data reported by the
authors of the scale indicated that surnmamv scores were
temporally stable (r [after 4 to 8 weeks]=.84) and successful-
ly disc r iminated patients wish multiple personality disorder
(MPD) from normalsand other pathologic al groups (Bern-
stein & Putnam, 1986).
Two laboratories have since independently confirmed
the discriminant. saliditv of the DES as a measure of dissocia-
tive psychopathology relative to different kinds of normal
comparison groups. For example, Ross, Norton, and Ander-
son ()988) reported that the median DES score of 17 Mf'D
patients was 40.7. Although this score was significantly lower
than the median DES score of 57.06 originally reported by
Bernstein and Putnam (1986) for their 20 MPD subjects, it
was still significantly higher than the median score of 4.9
observed for their normal subjects (medical students). In a
later study, Ross, Ryan, Anderson, Ross, and Handy (1989)
reported that normal median DES scores could vary from it
low of 4.8 (for elderly subjects), 7.9 (for college student
subjects), to a high of 17.7 (for adolescent subjects). DES
scores were inversely related to age and no significant differ-
ences were obser ved for sex.
Ensink and van Otterloo (1989) reported that 7 MPD
patients earned a median DES score of 55.4 while 13 patients
with a diagnosis of Dissociative Disorder not otherwise spec-
ified (DDNOS) earned a median DES score of 40.7. The median
DES scores for both dissociative groups, however, were sig-
nificantly higher than the median DES score of 16.3 for 80
psychology students.
Collectively, the findings from three different laborato-
ries have each demonstrated that patients with dissociative
psychopathology (either MPD or DDNOS) earn significantly
higher DES scores than various normal comparison groups.
However, there was significant variation among DES scores
within both the dissociative (range ofinedian DES scores=40.7
to 57.06) and normal groups (range of median DES
scores=4.38 to 17.7). This variation makes it difficult to
151
DISSOCIATION,No. September
  - I AMM !P 11  ~ `1P I "
estimate an optimal cutoff score for separating normals from
patients suffering from some type of dissociative disorder.
The purpose of the present study was fourfold:1) to
estimate the inter-rater reliability, temporal stability, and
internal consistency of DES scores in both normal and clin-
ical groups; 2) to provide additional evidence that normals
earn significantly lower DES scores than do patients with
different kinds of dissociative psyclropatholog- ; 3) to dern-
on.strate that MPI) patients earn significantly higher 1)lIS
scores than do patients with other types if dissociative
psychopathology (i.e., DDNOS); and 4) to examine the
consequences of using different DES cutoff scores to discrim-
inate between normals and dissociative disorder patients.
METHOD
DDNOS. Ninety-five percent of this patient group
were female and the average age was 35.1 (sd=6.17).
Forty-four percent had graduated from coll ege and,
or had earned an advanced college degree.
The 259 college students were all -undcrgradtu-
ates from the University of Illinois at Chicago who
completed the DES as part ofa study on hypnoti7abiliw
and personalityin order to earn course credit. Seventy-
five percent of this group were female and their
average age was 19.8 (sd=3.6).
Live judgement on the part of the rater, the intra-class
correlation method recommended byShrout & Fleiss (1979)
was used to estimate absolute and relative indices of inter-
rater agreement. Twenty DES protocols were independently
scored by four raters. The intra-class correlation of absolute
agreement. (called It X ,1] by Shrout & Fleiss, 1979 p. 423)
was .96 while the coefficient of relative agreement (called
ICC[3,I) br Shrout 8c Fleiss, 1979, p. 423) was .99.
The temporal stability of DES total scores was also as-
sessed using an intra-class correlation model. Thirty DD pa-
tients (15 \IPt) and 15 DDNOS) completed the DES twice within
approximately one month's time. The absolute temporal
stability coefficient was .93, while the relative temporal sta-
bility coefficient was .96. These findings indicate that DES
total scores are highly stable over time and that there are no
significant mean differences between testings.
Cronbach'salpha coefficient (( ronbach, 1951) was used
to estimate the internal consistencyof DES scores. The alpha
coefficient for the 33 MPD DES scores was .94, .94 for the 29
DDNOS DES scores, and .93 for the 259 student DES scores. In
addition, the alpha for the combined total sample of patients
and students (n=321) was .95.
TABLE 1
Parametric Data for DES Scores Among
t hree Different Groups
Procedure
The DES was routinely administered on an individual
basis to 62 inpatients at the Dissociative Disorders Inpatient
Unit of Rush North Shore Medical Center by either a psy-
chologist, nurse, or mental health worker. Thirty-three of
these patients met hod] DSM-III (American Psychiatric Asso-
ciation, 1980) and DSM-111-R (American Psychiatric
Association, 1987) criteria for a diagnosis of MPD
while the other 29 met these criteria for a diagnosis of
Group N Mean (Sd) Median
\-IPD 33 55.0 (19.2) 53.9
DI)NOS 29 40.8 (18.3) 14.8
STUDENTS 259 23.8 (14.11 22.9
Scoring of the DES
The DES was scored according to the graphic
rating method originally proposed and described by
Bernstein and Putnam (1986). The sum of the 28
items was divided by 28 to form an overall DES score
for each individual.
Statistical Analysis
Although Bernstein and Putnam (1986) origi-
nally recommended using nonparametric data ana-
lytic techniques with DES scores, they now seem to
advocate the use of more powerful statistical proce-
dures based on a general linear model (Eve Carlson,
personal communication, June 29, 1990) . Therefore,
all of the data analyses carried out in the present study
used an analysis of variance model (e.g., Guilford &
Fruchter, 1978).
RESULTS
Inter-rater Reliability, Temporal Stability, and
Internal Consistency of DES Scores
Since the scoring of DES items involves a subjec-
TABLE 2
Classification Rates and Errors for Different DES Cutoff Scores
DES % % %
Cutoff Correct False Positive False Negative
Score Classification Error Error
10 34 65 01
15 45 54 01
20 54 43 02
25 h3 34 03
30 70 25 05
35 76 18 06
40 82 12 06
45 87 06 07
50 87 03 10
55 87 02 11.
60 85 01 14
152
DISSOCIATION, Vol. I11, No. 3: September 11194
"IM ;'7 I 1 . 1 rr1 r 1 W P" 11   1.111 1
Discriminant Validity of DES Scores
The means, standard deviations, and median DES scores
for each patient group and the student sample are presented
in Table 1. NIP!) patients earned a mean DES score of 55.03
(sd=19.2). DDNOS patients earned a mean DES score of '40.8
(scl=18.3), and the students earned a mean DES score of 23.8
(sd=14.1). A one-way analysis of variance using group as the
independent variable and DES scores as the dependent vari-
able indicated that there were significant differences be-
tween groups (F[2,3181=73.0, p <.00O01). Two it priori
planned contrasts were then carried out to ascertain the
nature of these differences. The first contrast indicated that
the mean DES scores for the combined dissociative patient
group was significantly higher than the mean DES score for
thestudentgroup (113181=11.3, p<.001,one tailed test). The
second contrast indicated that the mean DES score for the
NIPD patients was significantly higher than the mean DES
score for DDNOS patients (t[318]=3.68, p <.001, one tailed
test). Thus, the present findings again confirm the discrim-
inant validity of DES scores. Patients with dissociative psy-
chopathology earn significantly higher DES scores than do
normals and MPD patients earn significantly higher DES
scores than do patients with other types of dissociative
psychopathology.
Developing DES Cutoff Scores
In order to assess the consequences of using different
DES cutoff scores to discriminate between patients with
dissociative psychopathology and normals, one must consid-
er three different values: 1) the percentage correctly classi-
fied; 2) the percentage of false positive error; and 3) the
percentage of false negative error. Table 2 presents these
values for various DES cutoff scores to discriminate between
the students and the combined patient group.
Examination of Table 2 suggests that a DES cutoff score
of 45 to 55 maximizes the percentage of correctly classified
(87%) while minimizing the false positive (2 to (3%) and false
negative (7 to 1 I%) error rates.
DISCUSSION
Collectively, the results of the present study provide
further support for the utility of the DES as a measure of
dissociative psychopathology. The inter-rater reliability for
the DES scoring procedure is excellent (absolute agreement.
=.96; relative agreement=.99) and DES scores were found to
he highly internally consistent (.94 in the MPD group; .94 in
the DDNOS group; .93 in the student group; and .95 in the
combined total sample). As reported earlier, patients with
dissociative disorders earn significantly higher DES scores than
do normals (Bernstein & Putnam, 1986; Ensink & van Otter-
lo, 1989; Ross, Norton, & Anderson, 1988) and MPD patients
earn significantly higher DES scores than do patients with
other kinds of dissociative psychopathology (Enskink & van
Otterlo, 1989). The findings also suggest that a DES cutoff
score of 45 to 55 will optimize the correct classification of
patients from normals while minimizing the rates of false
positive and false negative errors. In this regard, one must
also consider the possibility that some of the student group
may actually have had some type of DSM-111-R dissociative
disorder. I lowever, the present authors consider this possi-
bility to be extremely unlikely for two reasons. First, the
incidence of dissociative disorders in the general population
is very rare. Second, the first author worked in the same
psychology department clinic over a period of lour years
where the present student sample was drawn. During this
time period, not one student was ever diagnosed as suffering
from any type of dissociative disorder.
The results of the present study are encouraging and
suggest that the DES may be a valuable instrument in the
differential diagnosis of dissociative disorders from normals.
However, additional research is still necessary to further
substantiate the utility of the DES in discriminating disso-
ciative disorder patients from patients with other kinds of
psychopathology_
The authors would like to gratefully acknowledge the
assistance of Eve Carlson, Plt. D., who served as one of the
four raters in the present study. 
REFERENCES
American Psychiatric Association (198th). I)ia,gniostic aad statistical
manual of mental disorders (`3rd (id).
American Psychiatric Association. (1987). Diagnostic and statistical
manual of mental disorders (3rd. - revised). Washington. DC: Author.
Bernstein, E.M., & Putnam, E.W. (1986). Development, reliability,
and validity of.a dissociation scale.
174. 727-734.
Cronhach, l..J. (1951). Coefficient alpha and the internal structure of
tests. Psydiometrika, 16, 297-334.
Ensink, B.J.. &van Otterloo, D. (1989) . Avalidation of the dissociative
experiences scale in the Netherlands. DISSOCI47)A V, 2, 221-224.
Guilford, J. P.,&Flitch ter, B. (1978).Funadamen-talslatislicsinpsychologn
and education. New York: McGraw Bill.
Ross, C.A., Norton, G.R., & Ande r
experiences scale: a replication study. DISSOCIATION,1 (3), 21-22.
Ross, C. A., Ryan, L., Anderson, G., Ross, D. , & Hardy, L. (1989).
Dissociative experiences in adolescents and college students.
DISSOCIATION, 2,240-243.
Shrout, P.E., & Fleiss, J. L. (1979). Intr-aclass correlations: uses in
assessing rater reliability. Pslchnlogncel Bulletin, 86, 420-428.
153
DISSOCIATION,Vol. II1,No. 3: Seplember 090