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Eye movement desensitization and reprocessing in posttraumatic stress disorder: A pilot study using assessment measures
.I. Behav. Thu. & Exp. Prychrat. Vol. 25. No. 2, pp. I13-120. 1994. Elsevier Science Ltd Printed in Great Britain 0005-7916/94 $7.00 + 0 00
Pergamon 00057916(94)E0028-J
EYE MOVEMENT POSTTRAUMATIC
DESENSITIZATION AND REPROCESSING IN STRESS DISORDER: A PILOT STUDY USING ASSESSMENT MEASURES
DAVID FORBES, MARK CREAMER University
and PAMELA RYCROFT
of Melbourne
Summary - Spectacular claims have been made regarding the efficacy of eye movement desensitization and reprocessing (EMDR) in the treatment of posttraumatic stress disorder (PTSD), but almost entirely on the basis of patients’ reports and without objective criteria. This study reports on the treatment of eight patients with a diagnosis of PTSD who received EMDR treatment over four sessions. Assessment measures included two structured interviews, three self-report inventories, and the electromyogram (EMG). Assessments were conducted pre and posttreatment, and at 3.month follow-up. Despite some residual pathology at posttreatment and follow-up, significant improvements were obtained on all measures and across all PTSD symptom clusters. Compared with other treatments of PTSD, change was achieved in far fewer sessions.
traumatic stress disorder (PTSD). Although Shapiro points out that EMD may not eliminate all PTSD symptomatology, she notes that “the evidence clearly indicates that a single session of the EMD procedure is effective in desensitizing memories of traumatic incidents .” (1989a; p. 216). She further asserts that “. . enough information has been given here to achieve complete desensitization of 7530% of any individually treated trauma-related memory in a single 50-minute session” (1989a; p. 221). In a later paper (Shapiro, 1989b), that estimate was modified to 60-70%. Despite these claims, surprisingly few controlled studies have appeared in the literature since the technique was introduced. In her initial paper, Shapiro (1989a) reported on a study of 22 patients with PTSD who were randomly allocated to one session of EMD or a control treatment. However, as noted by Herbert and Mueser (1992), whilst dramatic results were reported for the active treatment, the study is seriously flawed. In particular, the only outcome
The technique of eye movement desensitization (EMD) has received considerable attention since it first appeared in the literature some years ago (Shapiro, 1989a, 1989b). Briefly, this technique involves the therapist eliciting rhythmic, bilateral eye movements from the client. At the same time, the client is asked to visualise an image of the relevant memory, internally repeat the negative self statement associated with the memory, and attend to the locus of any associated physiological distress. A revised version of the technique, eye movement desensitization and reprocessing (EMDR), was later developed by Shapiro (1991) and is now taught widely in workshop formats throughout the world; unfortunately, details of this revised procedure have yet to be published. The procedure is thought to be particularly effective in the treatment of post-traumatic stress disorder, in which the eye movements apparently facilitate reversal of the ill-effects of traumatic memories. Spectacular claims have been made for the success of EMDR in the treatment of post-
Requests for reprints should be addressed to Mark Creamer, Department Victoria 3052, Australia. 113
of Psychology,
University of Melbourne,
Parkville.
114
DAVID
FORBES. MARK CREAMER
data to be reported in detail were subjective in nature. The main criterion adopted was a reduction in SUDS (Subjective Units of Distress) scored on an 11 -point Likert scale (Wolpe, 1990). Following Shapiro’s original report on EMD, several case studies were published. Wolpe and Abrams (1991) discussed the successful treatment of a 43-year-old woman with PTSD using a combination of behavior therapy and EMD over several sessions. Puk (1991) reported on two cases of PTSD, both of whom showed remarkable improvements following one session of EMD. Marquis (1991) reported on the treatment of 78 cases with a variety of diagnoses using EMD; almost all showed significant improvement. Unfortunately, all of these case studies share with Shapiro’s original (1989a) study the objection that no objective or standardized measures of psychopathology were used to assess changes as a function of treatment. In all cases, estimates of treatment efficacy were based on verbal reports from the patient to the therapist. There is clearly a need for more objective studies investigating this potentially important intervention. The purpose of the present study was to evaluate the efficacy of EMDR in the treatment of PTSD by adopting a range of objective and/or standardized measurement strategies at pre and posttreatment and 3-month follow-up. The study was originally designed to include a waiting list control group; unfortunately, drop-out from that group was high and time constraints precluded the possibility of recruiting further subjects. Thus, no data from that group are reported and the remainder of this paper focuses exclusively on the active treatment group. Method Measures Several strategies were adopted to assess initial symptom severity, changes as a function of treatment and potential predictors of treatment response. (a) Structured
interviews.
The Structured
and PAMELA
RYCROfl
Interview for PTSD (SI-PTSD; Davidson, Smith & Kudler, 1989) was used to determine the presence and severity of PTSD. This interview contains 18 items corresponding to DSM-III-R criteria, each rated on a O-4 scale, with the total score ranging from 0 to 52. Davidson et al. (1989) reported a high level of internal consistency for the total interview (Cronbach’s alpha = .94) and a similar result was obtained with the current data set (Cronbach’s alpha = .96). Those subjects meeting the criteria for PTSD were further assessed using the Structured Clinical Interview for DSM-III-R (SCID-NP; Spitzer, Williams, Gibbon & First, 1988) in order to determine the presence of any comorbid diagnoses. This was included in order to investigate whether EMDR treatment effects would generalise to existing comorbid symptomatology and to detect the presence of any emergent pathology posttreatment. (b) Self-report measures. Three self-report scales were utilized. The Symptom Checklist-90Revised (SCL-90-R; Derogatis, 1977) comprises a list of 90 problems and complaints and was included to provide a broad index of psychological adjustment. The Global Severity Index (GSI), an overall measure of the number and severity of problems, is used in the current study as the best single indicator of current distress. The Impact of Events Scale (IES; Horowitz, Wilner & Alvarez, 1979) is a widely used 15-item questionnaire incorporating the two subscales of intrusion and avoidance. The Beck Depression Inventory (BDI; Beck, Rush, Shaw & Emery, 1979) was included to assess comorbid depression. (c) Suggestibility scale. Given the relative dearth of empirical data on EMDR, it was considered to be of value to investigate other processes that might help explain the dramatic results cited in existing EMDR studies. Suggestibility was selected as a pertinent area of investigation as the EMDR protocol includes a number of features reminiscent of hypnotic procedures. The Stanford Hypnotic Clinical Scale (SHCS: Morgan & Hilgard, 1975) was included in
Eye Movement Desensitization
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115
order to investigate the effects of suggestibility on treatment outcome. This clinician-rated scale records the presence or absence of five suggested responses as demonstrated by the subject, with scores ranging from 0 to 5.
traumatic event ranged from with a mean time of 10.60 Only two of the subjects traumatic incident within the sample relatively chronic.
(d) Psychological measures. Muscle tension (EMG) was assessed to provide a physiological correlate of clinical improvement. EMG electrodes were located on the left frontalis muscle. These measurements were recorded in arbitrary analogue to digital (A-D) conversion units. They consisted of mean scores over a 30 second sampling period and were taken under two conditions: (1) a baseline condition, where the subject was asked to imagine a neutral stimulus and (2) a trauma condition, where the subject was asked to access the traumatic memory. These conditions were recorded at each treatment session to assess between session changes and overall pre to posttreatment changes.
Design and Procedure
Subjects Subjects for this study were recruited from a variety of sources, including public sector psychiatric services, private practitioners, and a Veteran’s Counselling Service. They were informed that the study was designed to evaluate a specific treatment for posttraumatic stress and were required to sign a consent form prior to participation. The group comprised five males and three females. All subjects met the DSM-III-R criteria for PTSD at pretreatment. Exclusion criteria consisted of a current or previous diagnosis of organic mental disorder, schizophrenia, or paranoid disorder; depression severe enough to require immediate treatment, bipolar depression or psychotic depression; current alcohol or drug dependence; illiteracy in English. The subjects’ ages ranged from 22 to 46 with a mean age of 31.25 (SD = 9.49). The nature of the traumatic events reported included combat, sexual and nonsexual assault , and vicarious trauma. Of the eight subjects, six reported one trauma, one reported two, and one reported a history of three traumatic incidents. The time since the most recent
6 weeks to 26 years years (SD = 12.29). had experienced a last year, making the
All subjects were assessed initially using the SI-PTSD and the SCID interviews. Pretreatment self-report measures were completed and the suggestibility scale (SHCS) administered. Treatment began the following week and involved four, once weekly, 90-minute sessions. The decision to provide four treatment sessions was based on Shapiro’s (1991) statement that, in some cases, up to four sessions may be required for each event. Treatment was conducted by one male and one female therapist. Both therapists were registered psychologists and were trained in the use of EMDR by Francine Shapiro during a 3-day workshop conducted in July 1992. Both therapists had had the opportunity to practice the technique with a number of clients prior to commencement of this study. Treatment was carried out exactly as described by Shapiro (1992). This included the full revised EMDR protocol, including the targeting of a variety of relevant traumatic memories. EMG measures were taken at each session. Subjects were re-assessed using the SI-PTSD and the three self-report inventories one week following termination of treatment. Follow-up assessments were conducted three months following termination and included the SI-PTSD, the self-report inventories and the SCID (to assess any changes in comorbidity).
Results Diagnostic Issues All subjects met the criteria for a DSM-IIIR diagnosis of PTSD at pre-treatment, as assessed with the SI-PTSD. In terms of comorbidity, based on data from the SCID, three subjects also met the
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DAVID FORBES, MARK CREAMER and PAMELA RYCROFT
criteria for a DSM-III-R diagnosis of Major Depression. On follow-up, only one of these three subjects still met the criteria for a diagnosis of Major Depression. There was no evidence of any emergent comorbidity at follow-up. SI-PTSD data at pre and posttreatment and at 3-month follow-up are presented in Table 1. Univariate repeated measures analyses of variance (ANOVA) were performed on pre and posttreatment and 3-month follow-up data. Significant effects were found for each of the three symptom categories (re-experiencing, avoidance and hyperarousal), as well as for total PTSD severity. Planned contrast analyses (Winer, 1971) revealed significant improvement from pre to posttreatment in all areas, with no further change from posttreatment to follow-up. The proportion of patients showing clinically significant improvement was also investigated. Following the guidelines provided by Jacobson and Traux (1991), and the practice of Foa,
Rothbaum, Riggs and Murdock (1991), subjects were considered significantly improved if posttreatment (or follow-up) scores were more than two standard deviations below the mean of the pretreatment sample. Using the total SIPTSD score as a criterion measure, 75% (N = 6) showed significant improvement at posttreatment; this figure has dropped to 62% (N = 5) at followup. Despite improvements as a function of treatment, significant residual symptomatology was evident. Four subjects (50%) continued to meet the criteria for a full diagnosis of PTSD at both posttreatment and follow-up. In terms of specific symptom clusters, six, four and seven of the eight subjects met the diagnostic criteria for the reexperiencing, avoidance, and hyperarousal categories, respectively, at posttreatment. Seven, four and seven of the subjects met the criteria for the reexperiencing, avoidance, and hyperarousal categories at follow-up.
Table 1 Means, SDS Analyses of Variance (ANOVAS) and Contrust Analyses on the SI-PTSD and Self-Report measures (IES. BDI & SCLW-R:GSI) at pre and posttreatment and follow-up (N = 8)
SI-PTSD: Intrusion Avoidance Hyperarousal SI-F’l-SD: Total Self report: IES: Intrusion IES: Avoidance IES: Total BDI GSI
Pre to postcontrast analysis df (1.12)
Post to followup contrast analysis df(1,12)
F = 8.55 pi.01 F = 7.60 p<.Ol F = 5.89 p < .05 F= 10.11 p < .Ol
F = 9.46 p < .Ol F= 12.14 p< .Ol F = 8.28 p < .05 F = 14.27 p<.Ol
F= .73 n.s. F=.05 ns. F=.03 ns. F=.05 ns.
F = 5.82 p < .05 F = 8.09 p<.Ol F = 8.86 p<.Ol F = 5.29 p < .05 F = 3.79 p < .05
F=5.66 p < .05 F = 13.53 p<.Ol F = 12.58 p < .Ol F = 10.59 p < .Ol F = 6.46 p < .05
F= .85 n.s. F= .21 ns. F=.04 ns. F = 2.76 n.s. Fz.24 “.S.
PrEZ mea” (SD)
Post mean (SD)
Follow-up mean (SD)
ANOVA
9.00 (2.07) 14.75 (2.18) 14.25 (1.90) 38.00 (4.89)
5.87 (3.97) 9.00 (6.69) 10.37 (4.56) 25.25 (14.41)
5.58 (.93) 9.37 (5.75) 10.12 (4.49) 25.50 (13.68)
27.87 (5.22) 29.12 (7.41) 57.00 (11.42) 19.50 (11.90) 1.42
19.50 (8.68) 14.12 (11.15) 33.62 (18.72) 13.37 (9.16) 1.06
(.W)
(.59)
16.25 (9.06) 16.00 (10.14) 32.25 (17.44) 16.50 (12.03) 1.11 (.78)
(ffi)
Eye Movement Desensitization
and Reprocessing
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Self-Report Measures
Table 2
Data from the IES and BDI, as well as the Global Severity Index (GSI) from the SCL-90-R, are provided also in Table 1. As for the SI-PTSD data, univariate repeated measures ANOVAs were performed to assess differences among pretreatment, posttreatment and 3-month followup data. In line with findings from the SI-PTSD, significant effects were obtained on all measures. (With regard to the SCL-90-R subscales, only Interpersonal Sensitivity demonstrated a significant improvement.) Contrast analyses again revealed that differences on the self-report measures were accounted for by significant pre to posttreatment improvements, with no changes occurring between posttreatment and follow-up.
Means, SDS, and effect sizes for muscle tension (EMG: A-D units) at rest (baseline) and while imagining the trauma
Psychophysiological
Measure (EMG)
Mean reductions in EMG were noted across treatment sessions for both the baseline and trauma conditions (see Table 2). Unfortunately, some missing data render t-tests inappropriate to assess reduction in EMG levels between the first and last sessions. However, effect size analyses revealed large reductions in EMG from the first to last session in the baseline condition (.99), whilst moderate reductions were apparent in the trauma condition (.61). Of note is the large standard deviation associated with the trauma condition in the first session. Pearson correlation coefficients revealed a significant relationship between reductions in baseline levels of EMG and overall symptom improvement on the SI-PTSD (r = .96, p < .05). Correlations with SI-PTSD data were not significant in the EMG trauma condition (r = .47, n.s.) Subjective
Units of Distress (SUDS)
SUDS levels are routinely reported in discussions of EMDR and therefore will be provided for the current sample. A significant drop in SUDS ratings was recorded between the beginning (Mean = 8.50; SD = 2.00) and end (Mean = 3.00; SD = 3.58) of the first treatment session (t(7) = 3.79, p < .05).
Baseline Session 1: Session 2: Session 3: Session 4: Effect Size (14):
Factors Associated
1585.00 (875.00) 1293.00 (357.00) 94 1.oO (436.00) 943.00 (307.00) .99
Trauma 1825.00 1383.00 1075.00 947.00
(1542.00) (903.00) (537.00) (309.00) .61
With Treatment Response
Despite the small sample size, it was considered worthwhile to investigate factors potentially associated with treatment response, as this may provide speculation for further research. Pearson correlation coefficients were used to investigate the relationship between overall symptom reduction (in the total SI-PTSD score) and the variables of age, time since the trauma and suggestibility. Using pre and posttreatment improvement as the “dependent” measure, only suggestibility demonstrated a significant correlation (r = .86, p < .05). Further analyses revealed that this relationship was accounted for solely by reductions in the “avoidance” symptom cluster. However, using pretreatment to 3-month follow-up as the “dependent” measure, that relationship was no longer significant. Time since the trauma was the only variable demonstrating a significant correlation with total SI-PTSD improvement from pretreatment to follow-up (r = .81, p < .05); that is, increasing time since the trauma was associated with less improvement at follow-up following EMDR. This relationship was accounted for solely by reductions in hyperarousal.
Discussion The results of this pilot study must be interpreted cautiously due to the small sample size and the absence of a placebo treatment condition to control for nonspecific therapist effects.
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Nevertheless, the findings suggest that EMDR may be at least moderately effective in reducing symptomatology in all three PTSD symptom categories. These significant improvements, acquired over only four treatment sessions, were apparent from pre to posttreatment, with changes largely maintained at 3-month follow-up. Consistent findings were obtained across clinical interview, self-report, and psychophysiological measures. There is little in the current data to suggest that the technique is more efficacious for one PTSD symptom group than another (e.g., for intrusive rather than avoidant symptoms). Significant improvement was also noted at posttreatment in depressive symptoms; a nonsignificant deterioration on this measure was noted at follow-up. Despite these improvements, data from the SIPTSD and self-report measures suggest that significant pathology remained following treatment. This is highlighted by the finding that 50% of subjects still met the criteria for a full diagnosis of PTSD at both posttreatment and 3month follow-up. While at first sight such a finding is disappointing, it is comparable with the results of Foa et al. (1991). They compared stress inoculation training (SIT) with prolonged exposure (PE) in the treatment of rape-related PTSD. At posttreatment, 50% of the SIT group and 60% of the PE group still met the criteria for a full diagnosis; at 3-month follow-up, this figure had dropped to 45% for both groups. In terms of the proportions of patients showing significant improvement, Foa et al. (1991) reported that 71% (N = 10) of the SIT group and 40% (N = 4) of the PE group were significantly improved at posttreatment; at follow-up, the figures were 67% (SIT) and 56% (PE). These figures compare with 75% showing significant improvement at posttreatment and 62% at follow-up in the current study. In an earlier study, Brom, Defares & Kleber (1989) compared hypnotherapy, psychodynamic interventions and a newly-invented behavioral technique - “trauma desensitization”; and found all three treatments to be equally effective for PTSD. Posttreatment and follow-up scores on the Impact of Events Scale in the current study are
comparable with those of Brom et al., although the present sample scored considerably higher on the IES at pretreatment. Thus, although treatment effects of EMDR are limited, they are comparable with those of alternative interventions; and the treatment gains through its use in this study were achieved in only four sessions. Subjects in the Foa et al. (1991) study received nine treatment sessions, and those in the Brom et al. (1989) study between 14 and 18. It was the impression of the therapists that, in cases where significant progress was made, this progress tended to occur early in the treatment process and was frequently limited to the first two sessions. In cases where progress was slow or laboured in the first two sessions, additional treatment time offered little or no extra benefit. This implies that restricting treatment to four sessions did not hamper the efficacy of the procedure. An explanation for the high level of residual pathology may simply be that EMDR does not produce a “dose” effect. The procedure may be able to effect rapid improvement up to a point beyond which it contributes little extra benefit. In cases where the client appears not to respond to the procedure in the first session, persistence beyond this session is likely to add little or no value. It should be emphasised, however, that Shapiro (1991) recommends further EMDR sessions in cases of multiple trauma, with each event taking between one and four sessions to desensitize completely. An interesting anecdotal feature of the study was the incongruence between subjects’ reports of “being better” and having “gained a great deal” at posttreatment despite the fact that high levels of residual symptomatology remained on objective assessment. This reduced distress was reflected in the large reductions in SUDS reported by subjects and appears to be a feature of most papers published to date on EMDR (e.g., Kleinknecht & Morgan, 1992; Puk, 1991; Wolpe & Abrams, 1991). Considerable variation was evident between subjects’ responses to EMDR treatment, ranging from dramatic in some to little or no change in others. Therefore, it is of interest to examine factors that may be associated with response to
Eye Movement Desensitization
EMDR. Of the factors of age, time since the trauma, and suggestibility, only suggestibility correlated significantly with pre to posttreatment improvement. One explanation for this finding may be that suggestibility is a measure of a subjects ability to generate images. In general, progress tended to be related to the subject’s ability to visualise traumatic scenes. A significant negative correlation was evident between chronicity and longer term response to treatment (i.e., gains from pretreatment to followup). Although empirical research findings on this subject are limited, it is widely believed that chronic forms of PTSD are generally more treatment resistant (Peterson, Prout, & Schwartz, 1991). As with other interventions, it is possible that EMDR is optimally effective with more acute forms of the disorder. With regard to psychophysiological measures, it is interesting to note that reductions in baseline (resting) EMG were correlated with overall improvements in symptoms, but that changes in EMG during imagery of the trauma were not related to improved symptoms. This was noted despite overall group based reductions in EMG during imagery of the trauma occurring between sessions. This finding is in line with a recent study of exposure treatment in PTSD, which found that reductions in resting heart-rate were related to improved symptoms, but changes in heart-rate during imagery of the trauma were not related to changes in symptoms (Mueser, Yarnold, & Foy, 1991). It appears that changes in physiological measures of arousal at rest are more related to changes in symptoms than measures of arousal taken during imagery of the trauma. It may be speculated that overall symptom improvement may be more related to a reduction in the range of internal and external stimuli that are capable of activating the traumatic memory network than in the desensitization to the particular traumatic memory itself. Conclusions Our research provided some support for the technique of EMDR in the treatment of PTSD.
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Contrary to expectation, improvement was noted not only in intrusive symptoms, but also in avoidance and hyperarousal symptom clusters. However, the extent of improvement was limited, and significant pathology remained at posttreatment and follow-up. However, the same can be said of other contemporary treatments for PTSD (e.g., Brom et al., 1989; Foa et al., 1991; Keane, Fairbank, Caddell & Zimering, 1989). On the other hand, clearly, further studies are warranted. Acknowledgements - This research was funded in part by a Special Initiatives Grant from tbe University of Melbourne.
References Beck, A. T., Rush, A. J., Shaw, B. F. & Emery, G. (1979). Cognitive Therapy of Depression. New York, Guilford Press. Boudewyns, P. A., Stwertka, S., Hyer, L., Albrecht, W. & Sperr, E. (1993). Eye movement desensitization for VTSD of combat: a treatment outcome pilot study. The Behavior Therapist, 16,29-33. Brom, D., Defares, P. B. & Kleber, R. J. (1989). Brief psychotherapy for posttraumatic stress disorders. Journal of Consulting and Clinical Psychology, 57,607-612. Davidson, J., Smith, R. & Kudler, H. (1989). Validity and reliability of the DSM-III criteria for posttraumatic stress disorder. Experience with a structured interview. Journal of Nervous and Mental Disease, I77,336-341, Derogatis, L. (1977). SCL-90-R Administration, Scoring and Procedures Manual I. Baltimore, Clinical Psychometrics Research. Foa, E. B., Rothbaum, B. O., Riggs, D. S. & Murdoch, T. B. (1991). Treatment of post-traumtic stress disorder in rape victims: a comparison between cognitive-behavioral procedures and counseling. Journal of Consulting and Clinical Psychology, 59,715-723. Herbert, J. D. & Mueser, K. T. (1992). Eye movement desensitization: a critique of the evidence. Journal Of Behavior Therapy And Experimental Psychiatry, 23, 169-174. Horowitz, M. J., Wilner, N. & Alvarez, W. (1979). The impact of events scale: a measure of subjective stress. Psychosomatic Medicine, 41,209-218. Jacobson, N. S. & Traux, P. (1991). Clinical significance: a statistical approach to defining meaningful change in psychotherapy research. Journal of Consulting and Clinical Psychology, 59, 12-19. Keane, T. M., Fairbank, J. A., Caddell, J. M. & Zimering, R. T. (1989). Implosive (flooding) therapy reduces symptoms of PTSD in Vietnam combat veterans. Behavior Therapy 20, 245-261. Kleinknecht, R. A. & Morgan, M. P. (1992). Treatment of posttraumatic stress disorder with eye movement
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desensitization. Journal Of Behavior Therapy And Experimental Psychiatry, 23,43%49. Marquis, J. N. (1991). A report on seventy-eight cases treated by eye movement desensitization. Journal Of Behaviour Therapy and Experimental Psychiatry, 22, 187-192. Morgan, A. H. & Hilgard, J. R. (1975). The Stanford Hypnotic Clinical Scale. In E. R. Hilgard & J. R. Hilgard Hypnosis In The Relief Of Pain. Los Altos, California: William Kauffman. Mueser, K. T., Yarnold, P. R. & Foy, D. W. (1991). Statistical analysis for single-case designs: Evaluating outcome of imaginal exposure treatment of chronic PTSD. Behavior Modijkation. 15, 134-155. Peterson, K. C., Prom, M. F. & Schwartz, R. A. (1991). Posttraumatic stress disorder: a clinician’s guide. Plenum Press, New York. Puk, G. (1991). Treating traumatic memories: a case report on the eye movement desensitization procedure. Journal of Behaviour Therapy and Experimental Psychiatry, 22, 149-151. Shapiro, F. (1989a). Efficacy of the eye movement desensitisation procedure in the treatment of traumatic memories. Journal of Traumatic Stress, 2, 199224.
and PAMELA RYCROFT
Shapiro, F. (1989b). Eye movement desensitisation: a new treatment for post-traumatic stress disorder. Journal of Behaviour Therapy and Experimental Psychiatry, 20, 21 l-217. Shapiro, F. (1991). Eye movement desensitization and reprocessing procedure: from EMD to EMD/R - A new model for anxiety and related traumata. The Behavior Therapist, 14, 133-135. Shapiro, F. (1992). Eye Movement Desensitization And Reprocessing. Three-day training program: Melbourne, Australia. Spitzer, R. L., Williams, J. B. & Gibbon, M. (1987). Structured Clinical Interview For DSM-III-R (SCID). New York: Biometrics Research Department, New York State Psychiatric Institute. Winer, B. J. (1971). Statistical principles in experimental design (second edition). New York: McGraw-Hill Book Co. Wolpe, J. (1990). The practice of behavior therapy. Fourth edition. New York: Pergamon Press. Wolpe, J. & Abrams, J. (1991). Post-traumtic stress disorder overcome by eye movement desensitization: a case report. Journal of Behavior Therapy and Experimental Psychiatry, 22,39-43.
Pergamon 00057916(94)E0028-J
EYE MOVEMENT POSTTRAUMATIC
DESENSITIZATION AND REPROCESSING IN STRESS DISORDER: A PILOT STUDY USING ASSESSMENT MEASURES
DAVID FORBES, MARK CREAMER University
and PAMELA RYCROFT
of Melbourne
Summary - Spectacular claims have been made regarding the efficacy of eye movement desensitization and reprocessing (EMDR) in the treatment of posttraumatic stress disorder (PTSD), but almost entirely on the basis of patients’ reports and without objective criteria. This study reports on the treatment of eight patients with a diagnosis of PTSD who received EMDR treatment over four sessions. Assessment measures included two structured interviews, three self-report inventories, and the electromyogram (EMG). Assessments were conducted pre and posttreatment, and at 3.month follow-up. Despite some residual pathology at posttreatment and follow-up, significant improvements were obtained on all measures and across all PTSD symptom clusters. Compared with other treatments of PTSD, change was achieved in far fewer sessions.
traumatic stress disorder (PTSD). Although Shapiro points out that EMD may not eliminate all PTSD symptomatology, she notes that “the evidence clearly indicates that a single session of the EMD procedure is effective in desensitizing memories of traumatic incidents .” (1989a; p. 216). She further asserts that “. . enough information has been given here to achieve complete desensitization of 7530% of any individually treated trauma-related memory in a single 50-minute session” (1989a; p. 221). In a later paper (Shapiro, 1989b), that estimate was modified to 60-70%. Despite these claims, surprisingly few controlled studies have appeared in the literature since the technique was introduced. In her initial paper, Shapiro (1989a) reported on a study of 22 patients with PTSD who were randomly allocated to one session of EMD or a control treatment. However, as noted by Herbert and Mueser (1992), whilst dramatic results were reported for the active treatment, the study is seriously flawed. In particular, the only outcome
The technique of eye movement desensitization (EMD) has received considerable attention since it first appeared in the literature some years ago (Shapiro, 1989a, 1989b). Briefly, this technique involves the therapist eliciting rhythmic, bilateral eye movements from the client. At the same time, the client is asked to visualise an image of the relevant memory, internally repeat the negative self statement associated with the memory, and attend to the locus of any associated physiological distress. A revised version of the technique, eye movement desensitization and reprocessing (EMDR), was later developed by Shapiro (1991) and is now taught widely in workshop formats throughout the world; unfortunately, details of this revised procedure have yet to be published. The procedure is thought to be particularly effective in the treatment of post-traumatic stress disorder, in which the eye movements apparently facilitate reversal of the ill-effects of traumatic memories. Spectacular claims have been made for the success of EMDR in the treatment of post-
Requests for reprints should be addressed to Mark Creamer, Department Victoria 3052, Australia. 113
of Psychology,
University of Melbourne,
Parkville.
114
DAVID
FORBES. MARK CREAMER
data to be reported in detail were subjective in nature. The main criterion adopted was a reduction in SUDS (Subjective Units of Distress) scored on an 11 -point Likert scale (Wolpe, 1990). Following Shapiro’s original report on EMD, several case studies were published. Wolpe and Abrams (1991) discussed the successful treatment of a 43-year-old woman with PTSD using a combination of behavior therapy and EMD over several sessions. Puk (1991) reported on two cases of PTSD, both of whom showed remarkable improvements following one session of EMD. Marquis (1991) reported on the treatment of 78 cases with a variety of diagnoses using EMD; almost all showed significant improvement. Unfortunately, all of these case studies share with Shapiro’s original (1989a) study the objection that no objective or standardized measures of psychopathology were used to assess changes as a function of treatment. In all cases, estimates of treatment efficacy were based on verbal reports from the patient to the therapist. There is clearly a need for more objective studies investigating this potentially important intervention. The purpose of the present study was to evaluate the efficacy of EMDR in the treatment of PTSD by adopting a range of objective and/or standardized measurement strategies at pre and posttreatment and 3-month follow-up. The study was originally designed to include a waiting list control group; unfortunately, drop-out from that group was high and time constraints precluded the possibility of recruiting further subjects. Thus, no data from that group are reported and the remainder of this paper focuses exclusively on the active treatment group. Method Measures Several strategies were adopted to assess initial symptom severity, changes as a function of treatment and potential predictors of treatment response. (a) Structured
interviews.
The Structured
and PAMELA
RYCROfl
Interview for PTSD (SI-PTSD; Davidson, Smith & Kudler, 1989) was used to determine the presence and severity of PTSD. This interview contains 18 items corresponding to DSM-III-R criteria, each rated on a O-4 scale, with the total score ranging from 0 to 52. Davidson et al. (1989) reported a high level of internal consistency for the total interview (Cronbach’s alpha = .94) and a similar result was obtained with the current data set (Cronbach’s alpha = .96). Those subjects meeting the criteria for PTSD were further assessed using the Structured Clinical Interview for DSM-III-R (SCID-NP; Spitzer, Williams, Gibbon & First, 1988) in order to determine the presence of any comorbid diagnoses. This was included in order to investigate whether EMDR treatment effects would generalise to existing comorbid symptomatology and to detect the presence of any emergent pathology posttreatment. (b) Self-report measures. Three self-report scales were utilized. The Symptom Checklist-90Revised (SCL-90-R; Derogatis, 1977) comprises a list of 90 problems and complaints and was included to provide a broad index of psychological adjustment. The Global Severity Index (GSI), an overall measure of the number and severity of problems, is used in the current study as the best single indicator of current distress. The Impact of Events Scale (IES; Horowitz, Wilner & Alvarez, 1979) is a widely used 15-item questionnaire incorporating the two subscales of intrusion and avoidance. The Beck Depression Inventory (BDI; Beck, Rush, Shaw & Emery, 1979) was included to assess comorbid depression. (c) Suggestibility scale. Given the relative dearth of empirical data on EMDR, it was considered to be of value to investigate other processes that might help explain the dramatic results cited in existing EMDR studies. Suggestibility was selected as a pertinent area of investigation as the EMDR protocol includes a number of features reminiscent of hypnotic procedures. The Stanford Hypnotic Clinical Scale (SHCS: Morgan & Hilgard, 1975) was included in
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order to investigate the effects of suggestibility on treatment outcome. This clinician-rated scale records the presence or absence of five suggested responses as demonstrated by the subject, with scores ranging from 0 to 5.
traumatic event ranged from with a mean time of 10.60 Only two of the subjects traumatic incident within the sample relatively chronic.
(d) Psychological measures. Muscle tension (EMG) was assessed to provide a physiological correlate of clinical improvement. EMG electrodes were located on the left frontalis muscle. These measurements were recorded in arbitrary analogue to digital (A-D) conversion units. They consisted of mean scores over a 30 second sampling period and were taken under two conditions: (1) a baseline condition, where the subject was asked to imagine a neutral stimulus and (2) a trauma condition, where the subject was asked to access the traumatic memory. These conditions were recorded at each treatment session to assess between session changes and overall pre to posttreatment changes.
Design and Procedure
Subjects Subjects for this study were recruited from a variety of sources, including public sector psychiatric services, private practitioners, and a Veteran’s Counselling Service. They were informed that the study was designed to evaluate a specific treatment for posttraumatic stress and were required to sign a consent form prior to participation. The group comprised five males and three females. All subjects met the DSM-III-R criteria for PTSD at pretreatment. Exclusion criteria consisted of a current or previous diagnosis of organic mental disorder, schizophrenia, or paranoid disorder; depression severe enough to require immediate treatment, bipolar depression or psychotic depression; current alcohol or drug dependence; illiteracy in English. The subjects’ ages ranged from 22 to 46 with a mean age of 31.25 (SD = 9.49). The nature of the traumatic events reported included combat, sexual and nonsexual assault , and vicarious trauma. Of the eight subjects, six reported one trauma, one reported two, and one reported a history of three traumatic incidents. The time since the most recent
6 weeks to 26 years years (SD = 12.29). had experienced a last year, making the
All subjects were assessed initially using the SI-PTSD and the SCID interviews. Pretreatment self-report measures were completed and the suggestibility scale (SHCS) administered. Treatment began the following week and involved four, once weekly, 90-minute sessions. The decision to provide four treatment sessions was based on Shapiro’s (1991) statement that, in some cases, up to four sessions may be required for each event. Treatment was conducted by one male and one female therapist. Both therapists were registered psychologists and were trained in the use of EMDR by Francine Shapiro during a 3-day workshop conducted in July 1992. Both therapists had had the opportunity to practice the technique with a number of clients prior to commencement of this study. Treatment was carried out exactly as described by Shapiro (1992). This included the full revised EMDR protocol, including the targeting of a variety of relevant traumatic memories. EMG measures were taken at each session. Subjects were re-assessed using the SI-PTSD and the three self-report inventories one week following termination of treatment. Follow-up assessments were conducted three months following termination and included the SI-PTSD, the self-report inventories and the SCID (to assess any changes in comorbidity).
Results Diagnostic Issues All subjects met the criteria for a DSM-IIIR diagnosis of PTSD at pre-treatment, as assessed with the SI-PTSD. In terms of comorbidity, based on data from the SCID, three subjects also met the
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criteria for a DSM-III-R diagnosis of Major Depression. On follow-up, only one of these three subjects still met the criteria for a diagnosis of Major Depression. There was no evidence of any emergent comorbidity at follow-up. SI-PTSD data at pre and posttreatment and at 3-month follow-up are presented in Table 1. Univariate repeated measures analyses of variance (ANOVA) were performed on pre and posttreatment and 3-month follow-up data. Significant effects were found for each of the three symptom categories (re-experiencing, avoidance and hyperarousal), as well as for total PTSD severity. Planned contrast analyses (Winer, 1971) revealed significant improvement from pre to posttreatment in all areas, with no further change from posttreatment to follow-up. The proportion of patients showing clinically significant improvement was also investigated. Following the guidelines provided by Jacobson and Traux (1991), and the practice of Foa,
Rothbaum, Riggs and Murdock (1991), subjects were considered significantly improved if posttreatment (or follow-up) scores were more than two standard deviations below the mean of the pretreatment sample. Using the total SIPTSD score as a criterion measure, 75% (N = 6) showed significant improvement at posttreatment; this figure has dropped to 62% (N = 5) at followup. Despite improvements as a function of treatment, significant residual symptomatology was evident. Four subjects (50%) continued to meet the criteria for a full diagnosis of PTSD at both posttreatment and follow-up. In terms of specific symptom clusters, six, four and seven of the eight subjects met the diagnostic criteria for the reexperiencing, avoidance, and hyperarousal categories, respectively, at posttreatment. Seven, four and seven of the subjects met the criteria for the reexperiencing, avoidance, and hyperarousal categories at follow-up.
Table 1 Means, SDS Analyses of Variance (ANOVAS) and Contrust Analyses on the SI-PTSD and Self-Report measures (IES. BDI & SCLW-R:GSI) at pre and posttreatment and follow-up (N = 8)
SI-PTSD: Intrusion Avoidance Hyperarousal SI-F’l-SD: Total Self report: IES: Intrusion IES: Avoidance IES: Total BDI GSI
Pre to postcontrast analysis df (1.12)
Post to followup contrast analysis df(1,12)
F = 8.55 pi.01 F = 7.60 p<.Ol F = 5.89 p < .05 F= 10.11 p < .Ol
F = 9.46 p < .Ol F= 12.14 p< .Ol F = 8.28 p < .05 F = 14.27 p<.Ol
F= .73 n.s. F=.05 ns. F=.03 ns. F=.05 ns.
F = 5.82 p < .05 F = 8.09 p<.Ol F = 8.86 p<.Ol F = 5.29 p < .05 F = 3.79 p < .05
F=5.66 p < .05 F = 13.53 p<.Ol F = 12.58 p < .Ol F = 10.59 p < .Ol F = 6.46 p < .05
F= .85 n.s. F= .21 ns. F=.04 ns. F = 2.76 n.s. Fz.24 “.S.
PrEZ mea” (SD)
Post mean (SD)
Follow-up mean (SD)
ANOVA
9.00 (2.07) 14.75 (2.18) 14.25 (1.90) 38.00 (4.89)
5.87 (3.97) 9.00 (6.69) 10.37 (4.56) 25.25 (14.41)
5.58 (.93) 9.37 (5.75) 10.12 (4.49) 25.50 (13.68)
27.87 (5.22) 29.12 (7.41) 57.00 (11.42) 19.50 (11.90) 1.42
19.50 (8.68) 14.12 (11.15) 33.62 (18.72) 13.37 (9.16) 1.06
(.W)
(.59)
16.25 (9.06) 16.00 (10.14) 32.25 (17.44) 16.50 (12.03) 1.11 (.78)
(ffi)
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Self-Report Measures
Table 2
Data from the IES and BDI, as well as the Global Severity Index (GSI) from the SCL-90-R, are provided also in Table 1. As for the SI-PTSD data, univariate repeated measures ANOVAs were performed to assess differences among pretreatment, posttreatment and 3-month followup data. In line with findings from the SI-PTSD, significant effects were obtained on all measures. (With regard to the SCL-90-R subscales, only Interpersonal Sensitivity demonstrated a significant improvement.) Contrast analyses again revealed that differences on the self-report measures were accounted for by significant pre to posttreatment improvements, with no changes occurring between posttreatment and follow-up.
Means, SDS, and effect sizes for muscle tension (EMG: A-D units) at rest (baseline) and while imagining the trauma
Psychophysiological
Measure (EMG)
Mean reductions in EMG were noted across treatment sessions for both the baseline and trauma conditions (see Table 2). Unfortunately, some missing data render t-tests inappropriate to assess reduction in EMG levels between the first and last sessions. However, effect size analyses revealed large reductions in EMG from the first to last session in the baseline condition (.99), whilst moderate reductions were apparent in the trauma condition (.61). Of note is the large standard deviation associated with the trauma condition in the first session. Pearson correlation coefficients revealed a significant relationship between reductions in baseline levels of EMG and overall symptom improvement on the SI-PTSD (r = .96, p < .05). Correlations with SI-PTSD data were not significant in the EMG trauma condition (r = .47, n.s.) Subjective
Units of Distress (SUDS)
SUDS levels are routinely reported in discussions of EMDR and therefore will be provided for the current sample. A significant drop in SUDS ratings was recorded between the beginning (Mean = 8.50; SD = 2.00) and end (Mean = 3.00; SD = 3.58) of the first treatment session (t(7) = 3.79, p < .05).
Baseline Session 1: Session 2: Session 3: Session 4: Effect Size (14):
Factors Associated
1585.00 (875.00) 1293.00 (357.00) 94 1.oO (436.00) 943.00 (307.00) .99
Trauma 1825.00 1383.00 1075.00 947.00
(1542.00) (903.00) (537.00) (309.00) .61
With Treatment Response
Despite the small sample size, it was considered worthwhile to investigate factors potentially associated with treatment response, as this may provide speculation for further research. Pearson correlation coefficients were used to investigate the relationship between overall symptom reduction (in the total SI-PTSD score) and the variables of age, time since the trauma and suggestibility. Using pre and posttreatment improvement as the “dependent” measure, only suggestibility demonstrated a significant correlation (r = .86, p < .05). Further analyses revealed that this relationship was accounted for solely by reductions in the “avoidance” symptom cluster. However, using pretreatment to 3-month follow-up as the “dependent” measure, that relationship was no longer significant. Time since the trauma was the only variable demonstrating a significant correlation with total SI-PTSD improvement from pretreatment to follow-up (r = .81, p < .05); that is, increasing time since the trauma was associated with less improvement at follow-up following EMDR. This relationship was accounted for solely by reductions in hyperarousal.
Discussion The results of this pilot study must be interpreted cautiously due to the small sample size and the absence of a placebo treatment condition to control for nonspecific therapist effects.
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Nevertheless, the findings suggest that EMDR may be at least moderately effective in reducing symptomatology in all three PTSD symptom categories. These significant improvements, acquired over only four treatment sessions, were apparent from pre to posttreatment, with changes largely maintained at 3-month follow-up. Consistent findings were obtained across clinical interview, self-report, and psychophysiological measures. There is little in the current data to suggest that the technique is more efficacious for one PTSD symptom group than another (e.g., for intrusive rather than avoidant symptoms). Significant improvement was also noted at posttreatment in depressive symptoms; a nonsignificant deterioration on this measure was noted at follow-up. Despite these improvements, data from the SIPTSD and self-report measures suggest that significant pathology remained following treatment. This is highlighted by the finding that 50% of subjects still met the criteria for a full diagnosis of PTSD at both posttreatment and 3month follow-up. While at first sight such a finding is disappointing, it is comparable with the results of Foa et al. (1991). They compared stress inoculation training (SIT) with prolonged exposure (PE) in the treatment of rape-related PTSD. At posttreatment, 50% of the SIT group and 60% of the PE group still met the criteria for a full diagnosis; at 3-month follow-up, this figure had dropped to 45% for both groups. In terms of the proportions of patients showing significant improvement, Foa et al. (1991) reported that 71% (N = 10) of the SIT group and 40% (N = 4) of the PE group were significantly improved at posttreatment; at follow-up, the figures were 67% (SIT) and 56% (PE). These figures compare with 75% showing significant improvement at posttreatment and 62% at follow-up in the current study. In an earlier study, Brom, Defares & Kleber (1989) compared hypnotherapy, psychodynamic interventions and a newly-invented behavioral technique - “trauma desensitization”; and found all three treatments to be equally effective for PTSD. Posttreatment and follow-up scores on the Impact of Events Scale in the current study are
comparable with those of Brom et al., although the present sample scored considerably higher on the IES at pretreatment. Thus, although treatment effects of EMDR are limited, they are comparable with those of alternative interventions; and the treatment gains through its use in this study were achieved in only four sessions. Subjects in the Foa et al. (1991) study received nine treatment sessions, and those in the Brom et al. (1989) study between 14 and 18. It was the impression of the therapists that, in cases where significant progress was made, this progress tended to occur early in the treatment process and was frequently limited to the first two sessions. In cases where progress was slow or laboured in the first two sessions, additional treatment time offered little or no extra benefit. This implies that restricting treatment to four sessions did not hamper the efficacy of the procedure. An explanation for the high level of residual pathology may simply be that EMDR does not produce a “dose” effect. The procedure may be able to effect rapid improvement up to a point beyond which it contributes little extra benefit. In cases where the client appears not to respond to the procedure in the first session, persistence beyond this session is likely to add little or no value. It should be emphasised, however, that Shapiro (1991) recommends further EMDR sessions in cases of multiple trauma, with each event taking between one and four sessions to desensitize completely. An interesting anecdotal feature of the study was the incongruence between subjects’ reports of “being better” and having “gained a great deal” at posttreatment despite the fact that high levels of residual symptomatology remained on objective assessment. This reduced distress was reflected in the large reductions in SUDS reported by subjects and appears to be a feature of most papers published to date on EMDR (e.g., Kleinknecht & Morgan, 1992; Puk, 1991; Wolpe & Abrams, 1991). Considerable variation was evident between subjects’ responses to EMDR treatment, ranging from dramatic in some to little or no change in others. Therefore, it is of interest to examine factors that may be associated with response to
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EMDR. Of the factors of age, time since the trauma, and suggestibility, only suggestibility correlated significantly with pre to posttreatment improvement. One explanation for this finding may be that suggestibility is a measure of a subjects ability to generate images. In general, progress tended to be related to the subject’s ability to visualise traumatic scenes. A significant negative correlation was evident between chronicity and longer term response to treatment (i.e., gains from pretreatment to followup). Although empirical research findings on this subject are limited, it is widely believed that chronic forms of PTSD are generally more treatment resistant (Peterson, Prout, & Schwartz, 1991). As with other interventions, it is possible that EMDR is optimally effective with more acute forms of the disorder. With regard to psychophysiological measures, it is interesting to note that reductions in baseline (resting) EMG were correlated with overall improvements in symptoms, but that changes in EMG during imagery of the trauma were not related to improved symptoms. This was noted despite overall group based reductions in EMG during imagery of the trauma occurring between sessions. This finding is in line with a recent study of exposure treatment in PTSD, which found that reductions in resting heart-rate were related to improved symptoms, but changes in heart-rate during imagery of the trauma were not related to changes in symptoms (Mueser, Yarnold, & Foy, 1991). It appears that changes in physiological measures of arousal at rest are more related to changes in symptoms than measures of arousal taken during imagery of the trauma. It may be speculated that overall symptom improvement may be more related to a reduction in the range of internal and external stimuli that are capable of activating the traumatic memory network than in the desensitization to the particular traumatic memory itself. Conclusions Our research provided some support for the technique of EMDR in the treatment of PTSD.
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Contrary to expectation, improvement was noted not only in intrusive symptoms, but also in avoidance and hyperarousal symptom clusters. However, the extent of improvement was limited, and significant pathology remained at posttreatment and follow-up. However, the same can be said of other contemporary treatments for PTSD (e.g., Brom et al., 1989; Foa et al., 1991; Keane, Fairbank, Caddell & Zimering, 1989). On the other hand, clearly, further studies are warranted. Acknowledgements - This research was funded in part by a Special Initiatives Grant from tbe University of Melbourne.
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desensitization. Journal Of Behavior Therapy And Experimental Psychiatry, 23,43%49. Marquis, J. N. (1991). A report on seventy-eight cases treated by eye movement desensitization. Journal Of Behaviour Therapy and Experimental Psychiatry, 22, 187-192. Morgan, A. H. & Hilgard, J. R. (1975). The Stanford Hypnotic Clinical Scale. In E. R. Hilgard & J. R. Hilgard Hypnosis In The Relief Of Pain. Los Altos, California: William Kauffman. Mueser, K. T., Yarnold, P. R. & Foy, D. W. (1991). Statistical analysis for single-case designs: Evaluating outcome of imaginal exposure treatment of chronic PTSD. Behavior Modijkation. 15, 134-155. Peterson, K. C., Prom, M. F. & Schwartz, R. A. (1991). Posttraumatic stress disorder: a clinician’s guide. Plenum Press, New York. Puk, G. (1991). Treating traumatic memories: a case report on the eye movement desensitization procedure. Journal of Behaviour Therapy and Experimental Psychiatry, 22, 149-151. Shapiro, F. (1989a). Efficacy of the eye movement desensitisation procedure in the treatment of traumatic memories. Journal of Traumatic Stress, 2, 199224.
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Shapiro, F. (1989b). Eye movement desensitisation: a new treatment for post-traumatic stress disorder. Journal of Behaviour Therapy and Experimental Psychiatry, 20, 21 l-217. Shapiro, F. (1991). Eye movement desensitization and reprocessing procedure: from EMD to EMD/R - A new model for anxiety and related traumata. The Behavior Therapist, 14, 133-135. Shapiro, F. (1992). Eye Movement Desensitization And Reprocessing. Three-day training program: Melbourne, Australia. Spitzer, R. L., Williams, J. B. & Gibbon, M. (1987). Structured Clinical Interview For DSM-III-R (SCID). New York: Biometrics Research Department, New York State Psychiatric Institute. Winer, B. J. (1971). Statistical principles in experimental design (second edition). New York: McGraw-Hill Book Co. Wolpe, J. (1990). The practice of behavior therapy. Fourth edition. New York: Pergamon Press. Wolpe, J. & Abrams, J. (1991). Post-traumtic stress disorder overcome by eye movement desensitization: a case report. Journal of Behavior Therapy and Experimental Psychiatry, 22,39-43.