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By Judith L. Balk, MD, FACOG
Post-traumatic stress disorder (PTSD) is a fairly common disorder. Roughly 8-10% of the population will suffer from PTSD at some point in their lives. For victims of violent crimes such as rape, the rate of PTSD may be 60-80%.1
According to the DSM-IV, diagnostic criteria for PTSD include: 1) perceived or actual threat to life or physical integrity, accompanied by an emotional response of horror, helplessness, or intense fear; 2) re-experience of the trauma (e.g. flashbacks and nightmares); 3) avoidance of trauma-related stimuli and numbing of interest and affect; and 4) increased unwanted arousal, such as concentration difficulties, irritability, and insomnia. Specific criteria exist regarding the numbers of symptoms in each category that must be present.
Eye movement desensitization and reprocessing (EMDR) appears to be an effective adjunctive treatment for PTSD, but EMDR is difficult to study and may be dependent on eye movement.
Trauma can violate three basic premises: the belief in personal invulnerability, the perception of the world as meaningful, and the positive view of self.1 PTSD may occur from seemingly diverse events such as rape, combat, assault, and bereavement. These events are similar in that they all disturb one’s pre-existing view of the self and the world.
Treatment for PTSD
Treatment for PTSD strives to develop realistic assessments of the hazard from the trauma and the options for response that were available at the time of the trauma. Psychological approaches such as providing a safe environment in which to explore and re- experience the event are important, as is learning to conquer cue avoidance—cues that elicit memories of the trauma.
Both medication and psychological approaches have been used. The efficacy of treatments for both combat- and non-combat-related PTSD has been reviewed.2,3 Psychological therapies are more effective than drug therapies, which are more effective than controls. Selective serotonin reuptake inhibitors and carbamazepine are the most effective among the drug therapies; behavior therapy and EMDR are the most effective of the psychological treatments.3
EMDR is a controversial procedure that was developed by Francine Shapiro, PhD. In her initial 1989 paper, she wrote that she discovered the effect of the eye movements accidentally when she noticed that recurring, disturbing thoughts unexpectedly resolved:4
"Careful self-examination ascertained that the apparent reason for this effect was that the eyes were automatically moving in a multi-saccadic manner while the disturbing thought was being held in consciousness."
She noted that the thought disappeared, and if then deliberately retrieved, it was not emotionally disturbing. Dr. Shapiro began systematically using the eye movements for therapy, suggesting that the procedure had the capacity to desensitize a highly traumatic memory, produce cognitive restructuring, and cause substantial behavior changes.
The EMDR procedure incorporates some aspects of traditional psychotherapy with the eye movements. Overall, patients are asked to follow the therapist’s finger with their eyes. The therapist moves his/her finger very rapidly side to side 10-20 times as a means of eliciting rhythmic, bilateral saccadic eye movements. At the same time, the patient visualizes the traumatic event and internally repeats the associated irrational cognition or negative self-statement. This procedure may be repeated multiple times. The practice of EMDR has eight formal phases. These are explained in Table 1.
Trained physicians or psychologists perform this procedure in the office. Treatments last roughly 50 minutes each and typically are repeated several times, although studies range from one to 12 sessions.
Although the eye movements are crucial in the name of the procedure, "eye movement desensitization and reprocessing," some have questioned whether eye movements truly are necessary for the treatment to be effective. Several studies have found that keeping the eyes stationary during the procedure is as effective as standard EMDR. Others have replaced the eye movements with other forms of stimulation such as using a light-tracking apparatus or thumb tapping in time with a metronome.5 The eye movements are considered to be one element in the "package" of therapeutic elements. These other therapeutic elements are parts of standard therapeutic approaches, such as cognitive behavioral therapy. Although Dr. Shapiro may have noticed during a walk that her back-and-forth eye movements reduced the aversiveness of her troubling thoughts,6 no self-treatment approaches have been studied or recommended.
Mechanism of Action
One reason why EMDR is controversial is that it was not developed from a specific theoretical position; instead, it was developed from a serendipitous observation. That said, theories have evolved to explain a possible mechanism of action.
Shapiro postulates that with severe trauma, an imbalance occurs in the nervous system. The system holds, or is blocked by, the unprocessed disturbing information that is encoded neurologically. The eye movements, or any type of lateral stimulation, are proposed to facilitate information processing. With each set of eye movements, the disturbing information is thought to move at an accelerated rate further along the neuropsychological pathways, thus leading to neurobiological and psychological effects.7
Autonomic changes such as decreased blood pressure and heart rate have been found with EMDR compared to control conditions that were similar but had no eye movements.8 In addition, a single photon emission computed tomography (SPECT) study suggests that EMDR and successful treatment of PTSD do not reduce arousal at the limbic level, but instead enhance the ability to differentiate real from imagined threat.9
|Eight stages of EMDR|
Stage 1 Patient history and treatment planning
Stage 2 Preparation
Stage 3 Assessment
Stage 4 Desensitization and reprocessing
Stage 5 Installation of positive cognition
Stage 6 Body scan
Stage 7 Closure
Stage 8 Re-evaluation
Adapted from: Chemtob C, et al. Eye movement desensitization and reprocessing. In: Foa E, et al, eds. Effective Treatments for PTSD: Practice Guidelines from the International Society for Traumatic Stress Studies. New York: The Guilford Press; 2000:139-154.
"Gold standard" research methodology
1. Clear definition of PTSD or symptoms that are being targeted
2. Valid and reliable measures
3. Use of blinded evaluators
4. Assessor training
5. Replicable, specific treatment programs, detailed in treatment manuals
6. Unbiased assignment to treatment (randomization)
7. Rating of treatment adherence
Adapted from: Foa EB, Meadows EA. Psychosocial treatments for posttraumatic stress disorder: A critical review. Annu Rev Psychol 1997;48:449-480.
Performing randomized, controlled, blinded trials with EMDR is challenging. Methodological issues concern the varying presentation of the disease, the suitability of a control group, control treatment, outcome variables, and blinding.
Although PTSD has strict criteria for diagnosis, the most troubling symptoms vary between patients, a homogenous group of subjects to study is difficult to find, and the choice of a control group also is wide. One can compare EMDR to another psychological approach (and many exist), a medication, a waiting list or no-treatment control, or to a variant form of EMDR such as using no eye movements but having all of the other components. The chosen outcome variables must be valid, reliable, and indicative of all the major symptoms of PTSD. Comorbidity, such as depression and panic disorder, also must be taken into account. Finally, it is impossible to blind for either subject or researcher. Thus, ideally, the investigator performing the assessments will be blinded to treatment group. "Gold standards" for treatment outcomes studies of PTSD are listed in Table 2.10
The first controlled trial was published by Dr. Shapiro.4 In this study, 21 volunteers suffering from "traumatic memories" were randomized to receive either treatment with EMDR or a placebo treatment. Those who were assigned to placebo treatment received EMDR after the placebo treatment; this group became the delayed treatment group. A single session of EMDR successfully desensitized the subjects’ traumatic memories and altered their cognitive assessments of the trauma. These effects were maintained through the three-month follow-up period. The study lacked most of the gold standards noted in Table 2, including eligibility criteria, standardized measures, and blind evaluations.
A more rigorous study randomized 36 subjects with PTSD to wait list or non-wait list EMDR, image habituation training, or applied muscle relaxation.11 Assessor and self-reports evaluated outcome variables. All three treatment groups improved significantly compared to a wait list control. The authors concluded that EMDR is as helpful as the other approaches studied.
Other rigorous studies have compared standard EMDR to EMDR without eye movement. Seventeen Vietnam veterans with PTSD enrolled in a crossover study using the two treatment approaches.12 Both groups had modest to moderate overall improvement. The authors concluded that factors other than eye movements are responsible for EMDR’s therapeutic effect.
Other reviews and meta-analyses have been published on EMDR as a treatment for PTSD.6,13,14 One review argues that "EMDR provides an excellent vehicle for illustrating the differences between scientific and pseudoscientific therapeutic techniques."14 A different review concludes, "In sum, EMDR appears to be no more effective than other exposure techniques, and evidence suggests that the eye movements integral to the treatment, and to its name, are unnecessary."13 Another review concludes that "EMDR is an effective psychotherapy...EMDR’s relative efficacy in comparison to behavioral exposure therapies has yet to be established."7 Clearly, the evidence is conflicting. Heterogeneity in the research studies limits the conclusions that can be drawn.
Although a comparative conclusion is not yet possible, EMDR appears to be an effective adjunctive treatment for PTSD. Whether eye movements are necessary is unclear, as the role of the eye movements is unknown. Keeping the eyes stationary and other forms of stimulation may be effective. If eye movements are unnecessary, EMDR becomes another psychotherapeutic technique that may include helpful components of other psychotherapeutic techniques in one treatment package.
Patients suffering from PTSD should be encouraged to seek psychological therapy, which may include EMDR methodologies.
1. Solomon S. Psychosocial treatment of posttraumatic stress disorder. In Session: Psychotherapy in Practice 1997;3/4:27-41.
2. Solomon SD, et al. Efficacy of treatments for posttraumatic stress disorder. An empiric review. JAMA 1992; 268:633-638.
3. VanEtten ML, Taylor S. Comparative efficacy of treatments for post-traumatic stress disorder: A meta-analysis. Clin Psychol Psychother 1998;5:126-144.
4. Shapiro F. Efficacy of the eye movement desensitization procedure in the treatment of traumatic memories. J Traumatic Stress 1989;2:199-223.
5. Cahill SP, et al. Does EMDR work? And if so, why?: A critical review of controlled outcome and dismantling research. J Anxiety Disord 1999;13:5-33.
6. Chemtob C, et al. Eye movement desensitization and reprocessing. In: Foa E, et al, eds. Effective Treatments for PTSD: Practice Guidelines from the International Society for Traumatic Stress Studies. New York: The Guilford Press; 2000:139-154.
7. Spector J, Read J. The current status of eye movement desensitization and reprocessing (EMDR). Clin Psychol Psychother 1999;6:165-174.
8. Wilson DL, et al. Eye movement desensitization and reprocessing: Effectiveness and autonomic correlates. J Behav Ther Exp Psychiatry 1996;27:219-229.
9. Levin P, et al. What psychological testing and neuro-imaging tell us about the treatment of Posttraumatic Stress Disorder by Eye Movement Desensitization and Reprocessing. J Anxiety Disord 1999;13:159-172.
10. Foa EB, Meadows EA. Psychosocial treatments for posttraumatic stress disorder: A critical review. Annu Rev Psychol 1997;48:449-480.
11. Vaughan K, et al. A trial of eye movement desensitization compared to image habituation training and applied muscle relaxation in post-traumatic stress disorder. J Behav Ther Exp Psychiatry 1994;25:283-291.
12. Pitman RK, et al. Emotional processing during eye movement desensitization and reprocessing therapy of Vietnam veterans with chronic posttraumatic stress disorder. Compr Psychiatry 1996;37:419-429.
13. Davidson PR, Parker KC. Eye movement desensiti-zation and reprocessing (EMDR): A meta-analysis. J Consult Clin Psychol 2001;69:305-316.
14. Herbert JD, et al. Science and pseudoscience in the development of eye movement desensitization and reprocessing: Implications for clinical psychology. Clin Psychol Rev 2000;20:945-971.