The Eyes Have It: A look at EMDR

 
“How do you feel today?” my therapist asks me at the start of our session.
“Anxious,” I reply.
“Want to try some EMDR?”
I shrug. “OK.”
It’s not like anything else has helped to ease my social anxiety, except for psychopharmaceuticals.
“What’s EMDR?”
My therapist explains that it’s a technique often used to treat Post-Traumatic Stress Disorder.  She says something about eye movement and reprocessing traumatic memories and feelings, comparing it to defragmenting a computer (perhaps in an attempt to speak the language of my generation). She hands me her EMDR equipment: headphones that I slip over my ears and two small, round disks, one to hold in each hand. For the rest of the hour I sit with my eyes closed, thinking about panic-inducing situations and trying to feel that anxiety as the disks pulse and headphones beep, synchronized and alternating left and right.
 
I did not understand my therapist’s explanation of EMDR. A brief Internet search confused me more. Eye Movement Desensitization and Reprocessing? I didn’t do anything with my eyes! Used to treat sufferers of Post-Traumatic Stress Disorder? I have social anxiety, not PTSD! Since the initial search I have learned more about EMDR, and I have decided to write my first Bio202 paper about it in hopes of lessening the confusion others have about the therapy. It could be helpful to read a previous student’s web paper on EMDR, because she touches on aspects I have chosen not to discuss.
 
EMDR is a relatively new therapy, originally conceived of by psychologist Francine Shapiro in 1987 during a walk in the park. She noticed that her anxiety surrounding distressing thoughts decreased with “saccadic” eye movements. Based on her experience, Shapiro then developed a procedure to use on patients suffering from PTSD, and in her own clinical trials she found it to be significantly more effective at desensitizing anxiety than cognitive behavioral therapies. She coined it “Eye Movement Desensitization and Reprocessing”, or EMDR for short, and its efficacy and mechanisms of action have been subject to controversy since (1).
 
A quick PubMed search for EMDR yields over 200 results. It is apparent that researchers want to know if it works better than other therapies, and if so, why and how it works. As with nearly everything else regarding the brain, not much is known or agreed upon. Since Shapiro developed the therapy, her official EMDR website contains more information about the therapy than any other website I’ve visited, but since Shapiro developed the therapy, I will try not to rely too heavily on her as a source in an attempt to present unbiased information.
 
Shapiro’s standard procedure for EMDR therapy includes a three-pronged protocol overseeing eight phases, which are to be implemented at the appropriate point in each session of the treatment (6). Each session should be 60-90 minutes. Shapiro asserts that “a single trauma can be processed within 3 sessions in 80-90% of the participants” (1). More depth and specificity about her standard procedure can be found in her book, EMDR: Basic Principles, Protocols, and Procedures, 2nd Edition, parts of which can be read online on amazon.com (see: 6).
 
Shapiro single-handedly developed EMDR, and initially she personally trained other psychotherapists in her methods. Now psychotherapists can be trained by other therapists, or they can train themselves by reading a book, though the latter method does not officially qualify as training (1). As long as the therapist is implementing eye movements rather than tactile pulsers or audio stimuli, he or she does not need to buy any equipment. I could buy the book online and give my anxious friends EMDR therapy (Lengthy side note: Interestingly, as skeptics like to point out, Shapiro’s undergraduate degree is in English Literature and her doctorate is from an unaccredited and now defunct school, the Professional School of Psychological Studies in San Diego. Her “personal data” is available on her official EMDR website (1). Further investigation shows that while the Professional School of Psychological Studies was unaccredited, it was authorized by the State of California (4). Personally, I do not think the school’s lack of accreditation discredits EDMR since there have been many studies conducted by presumably “real” researchers other than Shapiro showing the therapy to be effective. It is unfortunate that some let this stand in the way of recognizing that EMDR is empirically proving to be an effective treatment). Even though there is one standard procedure for EMDR, it is unlikely that all experimenters in their research on EMDR are using the exact same protocol. Also, having read many abstracts of EMDR studies on PubMed, I can say the studies vary on the number of sessions and whether or not they are treating a single trauma experience or multiple trauma experiences.
 
So, is EMDR effective at treating PTSD? The conflicting results of the studies are confusing. Numerous problems with EMDR studies can confound the conclusions. Common to any study are methodological problems. Another issue, as evidenced by Perkins and Rouanzoin, is that many studies omit data or context, misreport or misstate data, and/or contain data contradictory to other researchers’ sources of confusion (5). Among the abstracts on PubMed of studies comparing the efficacy of EMDR to Prolonged Exposure (PE), there always seem to be a few patients in the PE group who drop out, while the EMDR group has little or no dropouts. There could be many reasons for this, the most sensible to me being that EMDR is not as difficult to endure. However, one cannot assume this is the case, and either way, I think it can confound the results.
 
One problem with many studies is a truncated protocol (5, 3). While EMDR has proven to be more efficient than other therapies, and while patients can experience anxiety desensitization after only one session, it is important to remember that it still takes multiple sessions to be effective (it may be helpful to point out that for these purposes, “effective” means “until the patient can no longer be diagnosed with PTSD”). I believe this may be where some of the confusion lies in comparing EMDR to PE. They are both effective treatments, but EMDR is generally found to be more efficient, and I think this sometimes gets translated into “more effective”. If, however, there are too few sessions and therefore the EMDR protocol is truncated, its effects will likely be incomplete (5, 3). Studies show that if steps of the procedure are omitted or inadequately applied, patients will experience no treatment effect or only partial decrease in anxiety (3). Also, the more traumatic events the patient has experienced, the more sessions they will probably need to treat PTSD effectively (3).
 
If one ignored all the known shortcomings of published studies and assumed all conclusions and results were accurate, one would find that overall, EMDR is an effective treatment for PTSD, that it is more efficient than other therapies, and that it is sometimes more effective than other therapies. For the remainder of this paper, I will assume that EMDR is an efficient and effective treatment for PTSD. It is always good to keep in mind, however, that just because something is a scientific study, doesn’t automatically make it true (or “less wrong”).
 
How can saccadic eye movements lead to safer memories? Perhaps they don’t. Eye movements, or dual attention stimuli, certainly distinguish EMDR from other therapies, but aren’t necessarily indispensable. Studies aimed at determining if eye movements are essential to the efficacy of EMDR have mixed results (1, 8). It has been argued that those dismantling studies have methodological flaws, such as too few patients, and are not helpful (7, 8). On the other hand, it is generally agreed that eye movements reduce the vividness and emotional distress of the memories and increase memory recall (1, 7). Few studies have been done to explore the effects of other dual-attention stimuli (7), such as the method my therapist employed, though it is believed they work the same way and are equally effective (8). If dual attention stimuli are not necessary, then other exposure-based therapies should work as rapidly as EMDR, but they do not, which points to some level of significance of dual attention stimuli (8).
 
Many people theorize how EMDR might work, and Konkle has summed up six prominent hypotheses to be: the “(1) synchronization of the two hemispheres, (2) de-conditioning caused by a relaxation response, (3) “jump-start” of a process similar to that of REM sleep, (4) the initiation of an orienting response, (5) the promotion of thalamocortical temporal binding in 40 Hz neural oscillation range which helps to integrate somatosensory, sensory, cognitive and affective material, and (6) the activation of the cerebellum, setting off a sequence of information processing which activates the thalamus and eventually the frontal lobes, increasing dorsolateral and orbitofrontal processing” (7).
 
The hypothesis I find most interesting is Dr. Robert Stickgold’s, which I believe combines hypotheses 3 and 4 listed above. Stickgold describes PTSD as a result of improper memory processing. Memories are initially formed in the limbic system, with the hippocampus playing a large role, and are referred to as episodic memories. The amygdala is responsible for the emotions associated with these memories. When one “remembers” an event in the episodic memory, they experience it very vividly. As time goes by, the brain transfers important information (admittedly, I’m not sure what the brain deems “important” and “waste of space”) to the semantic memory in the neocortex. Since this type of memory processing occurs in the same brain areas as new memory formation and current sensory input processing, researchers believe a large part of memory consolidation occurs during sleep. REM sleep is especially important for semantic memory integration (2).
 
Stickgold explains that in the case of PTSD, the episodic memory does not get integrated into the semantic memory, so it remains in the limbic system in its strong, original form. He has deduced from brain imaging studies that traumatic memories get consolidated during REM sleep and theorized that PTSD may interfere with the way the brain processes memories during REM sleep. Therefore saccadic eye movements could “jump start” the brain’s REM mechanisms (2).
 
But what about other forms of dual attention stimuli that don’t involve eye movements? All dual attention stimuli cause an orienting response; that is, because the stimuli are alternating sides of the body, the brain must continuously reorient its attention. As a result, the brain begins reprocessing memories into the semantic memory, just as it does during REM sleep. The traumatic memories get integrated into the semantic memory and then fade away from the episodic memory (2). This offers one explanation for a patient’s anxiety desensitization following EMDR therapy.
 
Even though EMDR was originally developed to treat PTSD, it is now being used to treat a variety of other disorders, including other anxiety disorders, dissociative disorders, personality disorders, somatoform disorders, ADHD, Dysmorphic Body Disorder, eating disorders, substance abuse, depression, and more (3). The vast majority of the clinical studies done on EMDR use it to treat PTSD, not other disorders; therefore it is unknown how effective EMDR is at treating other disorders. If in the future we find that it is effective at treating more than just anxiety disorders, then we must understand what these disorders or what these patients all have in common. For now, I think it’s reasonable to postulate that perhaps what these patients share is trauma. Simply enduring a traumatic event does not merit one a PTSD diagnosis. Often traumas can lead to other conditions and disorders (8). If this is the case, EMDR should be a treatment option to be considered alongside other therapeutic modalities.
 
The fact that EMDR’s mechanisms of action are not understood should not be disconcerting. Just think about how many people take psychopharmaceuticals without knowing how they work. Ask any psychiatrist why an antidepressant works; I doubt you’ll get a straight answer. It is difficult to know what alleviates a person’s depression -- was it the pharmacotherapy? Was it talk therapy? Was it a change in diet or exercise? Was it alternative therapies? It is likely that it was a combination of many things. Understanding the effectiveness of EMDR is a similar situation. Many different elements make up the EMDR treatment process. Some parts hint at exposure therapy, some at cognitive behavioral, some at other talk therapies, and as self-evidently, EMDR also relies on the integration of dual-attention stimuli. Much like the mind itself, EMDR is greater than the sum of its parts.
 
 
 
Sources referenced:
 

1. Francine Shapiro's EMDR website
2. EMDR: A Putative Neurobiological Mechanism of Action
   
3. EMDR: Why the Controversy?
   
4. Another Questionable "Professional Credential"
   
5. A critical evaluation of current views regarding eye movement desensitization and reprocessing (EMDR): Clarifying points of confusion
6. Eye Movement Desensitization and Reprocessing: Basic Principles, Protocols, and Procedures, 2nd Edition
   
7. EMDR -- Twenty Years Later
   
8. Eye Movement Desensitization and Reprocessing: Is Psychiatry Missing the Point?