# EMDR Therapy and Its Effects on the Brain

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- Page title: EMDR Therapy and Its Effects on the Brain | Assoc. Prof. Dr. Alişan Burak Yaşar

> How does EMDR promote recovery? Three theories explaining bilateral stimulation and recent research published in Nature and Molecular Psychiatry.

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# EMDR Therapy and Its Effects on the Brain

April 1, 2020Articles in Bilim ve Ütopya

[Görsel: EMDR Therapy and Its Effects on the Brain]

EMDR therapy is one of the most widely discussed therapies today. We frequently hear the name EMDR in scientific research, from psychotherapists, and from patients.

## First-Line Treatments for Disorders

Today, there are more than 100 psychotherapy approaches with demonstrated effectiveness, supported by varying amounts of research for different disorders. Other “techniques” that claim to offer treatment without any scientific evidence, which we can currently regard as quackery and which do more harm than good, outnumber these by more than ten to one. An important ethical principle in our assessment interviews with people seeking treatment is that, unless the intervention is part of a scientific study with ethical approval, patients should be offered the treatment recommended as first-line for their condition by the latest scientific evidence. At the initial consultation, we explain to our patients which treatment is currently the highest-priority scientific recommendation for their disorder and approximately how long it may take to help. Treatment recommendations are informed not by experience with one or two cases, but by research articles known as “meta-analyses,” which bring together hundreds or thousands of studies—research on research. Authorities in the field then develop guidelines based on this extensive body of data. Sometimes, statements in the media or the community such as “this helped my neighbor” receive more attention than guidelines, even though they cannot qualify even as a case report, since case studies also have rigorous scientific standards. This poses a very significant obstacle to appropriate treatment. From this perspective, EMDR therapy and Cognitive Behavioral Therapy (CBT) are currently recommended as first-line treatments for Post-Traumatic Stress Disorder (PTSD) in dozens of different scientific guidelines. Accordingly, someone with PTSD or a trauma-related disorder is first informed about these treatments, and they may be recommended after other circumstances are taken into account. Numerous controlled scientific studies have also been published showing that EMDR therapy is beneficial for depression and many other disorders. Research into the scientific effectiveness of a technique is therefore very important. In addition to whether it works, researchers also investigate how it works. However, the question “Does it work?” is more important than “How does it work?” Since we have a good understanding of whether EMDR works, this article will explore how it works, particularly the evidence concerning its effects on the brain and its mechanisms. Our fellow clinicians contributing to this issue have already shared detailed information about what EMDR therapy is, what it offers, and how it originated.

## Bilateral Stimulation in EMDR Therapy

First of all, although EMDR stands for Eye Movement Desensitization and Reprocessing, it is now a therapy that also uses techniques other than eye movements. F. Shapiro, who developed the therapy and whom we lost last year, captured the essence of this point by saying, “If I had the opportunity to name it today, I would call it reprocessing therapy.” Unlike other therapies, EMDR uses a particularly interesting method. At a specific stage of treatment, which follows a dedicated protocol and sequence, bilateral stimulation is administered while the person focuses on various stimuli associated with the distressing experience. Bilateral stimulation may take the form of eye movements, as it did when it was first discovered. For example, while focusing on a distressing memory, the person continues therapy by following the therapist’s fingers, moving their eyes alternately to the right and left. Although this was how the method was discovered, subsequent studies showed that alternating stimulation applied to the two sides of the body, or alternating sounds delivered to the right and left ears, also provide bilateral stimulation, just as eye movements do. Some studies suggest that bilateral stimulation through eye movements is still the most effective, while others report no difference between types of bilateral stimulation. Today, EMDR devices developed to improve comfort for therapists who conduct many sessions a day and for their clients are also used during EMDR therapy; I have also served as a consultant on their development. These devices provide bilateral stimulation through vibration, lights, and headphones and can be used during sessions.

## A Mysterious Technique: Fingers or Devices During Sessions

As EMDR developed into the fully scientifically accepted therapy it is today, this unusual in-session practice attracted considerable interest and criticism. Unlike other psychotherapy practices, a therapy in which the therapist used a machine, guided the client’s eyes to the right and left with hand movements while talking, or tapped the client’s knees during conversation was quite different from earlier schools of therapy. Because of these unusual features, many authorities were initially quite skeptical of EMDR therapy. However, scientists make judgments based on scientific evidence rather than unusual appearances or personal opinions. Through the efforts of leading scientists who devoted tremendous work to this field, data documenting positive effects in millions of people demonstrated that the therapy was effective and safe, leaving no scientists uncertain on this point.

## How Does Bilateral Stimulation Promote Recovery?

Despite all this, an important question raised from the very beginning remains a topic of debate. How does this therapy—and, by extension, its important component, bilateral stimulation—help people recover? How do bilateral stimulation and the therapy’s specific protocols sometimes turn a memory, such as a traffic accident or harassment, into a faint, distant image in the mind, even in a single session? Moreover, as this image fades, the distressing thoughts and unpleasant bodily sensations associated with the event disappear. This was a very important question and area of research.

## What Do Psychotherapies Do in the Brain?

In fact, there are dozens of scientifically effective psychotherapy approaches, just like EMDR. Today, there is even a scientific discipline called neuropsychoanalysis, which examines the effects on the brain of psychoanalysis, the forefather of psychotherapies. Nevertheless, we still know very little about the effects of other psychotherapies on the brain. Even our knowledge of the mechanisms through which antidepressants promote recovery remains far from absolute certainty. We know that they help people recover, but we do not yet fully understand “how.” In fact, even physics, which we might call the forefather of the sciences, continues to investigate, for example, how gravitational attraction affects us and through which invisible particles we are pulled toward the ground. There are unknowns there, too. The distance between science and absolute knowledge remains vast, but despite our limitations, we certainly have no better tool than science. Thus, although physics cannot fully explain exactly how gravity works, we know that gravitational attraction exists, and that by establishing various coefficients we can predict its effects. We might say that the situation in psychiatry is somewhat similar to that in physics...

## Why Is There So Much Interest in EMDR?

There are, however, several important features that explain why recent brain research has increasingly focused on EMDR. 1. EMDR therapy can sometimes produce very substantial changes even in a single session. Improvements that may take weeks and homework assignments in other therapies can sometimes be observed immediately during an EMDR session, right in the therapy room. It is therefore possible to view the session as a laboratory setting and investigate what happens in that moment. 2. Bilateral stimulation, one of the key features of EMDR therapy, has a very rapid effect on desensitization and the reprocessing of memories and information. A physiological bodily intervention without side effects must have a direct counterpart in the brain. For these and many other reasons, EMDR and the brain have recently been studied far more extensively than other therapies, and this research seems likely to grow further.

## Theories About How EMDR Promotes Recovery

Until 2019, in my talks at conferences and panel discussions, I would explain that although we were very familiar with the evidence for EMDR’s benefits, as described above, our scientific knowledge of its mechanisms of action was very limited, as with all other therapies. I would then describe the three main theories of how EMDR works as follows.

1)From a neurobiological perspective, it has been proposed that eye movements or other forms of bilateral stimulation increase communication between the cerebral hemispheres. According to this model, PTSD symptoms result from a disruption in memory processing. Bilateral eye movements facilitate interaction between the two cerebral hemispheres and stimulate information processing by increasing the activation and connectivity of brain cells called neurons. Ultimately, by facilitating the integration of episodic memory, which concerns recollections, with semantic memory, described here as memory relating to the self, they improve the capacity to assimilate the traumatic event. Electrophysiological studies have supported this model. During bilateral stimulation, as is known, vibration or stimulation applied to the right side of the body activates the left side of the brain, while stimulation applied to the left side of the body is reflected in the right side of the brain; this alternating process therefore strengthens connections between the hemispheres.

2)Eye movements lead to physiological changes similar to those that occur during the REM (rapid eye movement) stage of sleep. You have probably observed people sleeping... Just as people’s eyes move rapidly during the stage we call REM sleep, in this second model of EMDR, episodic memory is integrated into semantic memory in a manner similar to what occurs during sleep. Repeated bilateral eye movements activate neurological mechanisms resembling the processing that takes place during REM sleep, enabling traumatic memories to be integrated in a way that allows them to be left behind.

3)One of the hypotheses about EMDR therapy’s mechanism of action that has received the most research support is that eye movements and other forms of bilateral stimulation, whether tactile or auditory, disrupt working memory. As you know, a computer has RAM. If you open too many files or programs, RAM can become overloaded. Its counterpart in the brain is the concept of working memory. Working memory has a limited capacity. When a person focuses on both a memory and bilateral stimulation during therapy, this capacity is exceeded. This can allow access to the traumatic memory without experiencing intense emotion. In addition, as we know from previous research supporting this account of the therapy, repeatedly moving the eyes up and down, for example, activates the parasympathetic nervous system and promotes relaxation. Eye movements have been shown to reduce both the vividness of the traumatic memory and its associated emotional charge. They also increase attentional flexibility. According to this theory, eye movements during therapy spontaneously stimulate parasympathetic activity. Because sympathetic activity associated with fear and anxiety decreases while parasympathetic activity increases, the person can access traumatic memories more comfortably and process them in a way that allows them to be left behind as memories of the past. This enables information to be processed and adaptive connections to be established in memory.

## Recent Research on How EMDR Promotes Recovery

As I mentioned, this was the extent of the theoretical knowledge I presented at last year’s conferences. However, as noted above, interest in EMDR therapy, which uses an unusual method such as bilateral stimulation and is highly effective, has grown so much that several of the world’s leading journals, notably Nature, published very important studies on EMDR in 2019. As I will discuss shortly, we now know more about EMDR’s effects on the brain and have even observed effects related to EMDR therapy in mice.

An article published in Nature on February 13, 2019, with a title particularly fitting for our discussion, “Travmatik Stres için Esrarengiz Tedavinin İpuçları” (Clues to an Enigmatic Treatment for Traumatic Stress), presented highly significant research into EMDR’s mechanisms of action using experiments in mice. In this study, mice traumatized within the experimental model were exposed to a trauma-triggering stimulus and began behaving as if they were reliving the trauma, in a manner often seen in patients with PTSD. They were divided into three groups. One group was simply exposed repeatedly to the trigger. Could exposure to the fear alone allow them to become accustomed to it? Another group received alternating right-left lights without any trigger. A third group received both the trigger and bilateral lights... As in EMDR, bilateral stimulation combined with mild triggering of the traumatic memory significantly reduced fear behaviors in the mice compared with the other two groups. The experiment also investigated another claim made by some scientists: could the lights promote recovery simply by distracting attention? In a part of the experiment using random rather than bilateral lights, no improvement was observed. The study showed that, when paired with a procedure targeting the traumatic memory according to the EMDR protocol, desensitization occurred only with bilateral stimulation. The same researchers also proposed that EMDR changes the balance between various active circuits, or networks, in the brain. They suggested that circuits supporting fear extinction became active rather than the neurological circuits that maintain fear, and developed a hypothesis about this pathway. According to the hypothesis, the pathway involves regions called the superior colliculus, mediodorsal thalamus, and basolateral amygdala. To test it, the researchers reasoned that if bilateral stimulation really worked this way, then damaging these regions, for example through laser ablation, should prevent bilateral stimulation from resolving fear in the mice. As predicted, mice with damage to these regions showed no improvement associated with bilateral stimulation. Thus, bilateral stimulation, which activates adaptive pathways rather than fear pathways, was found to involve these three brain regions.

This study offers a neurobiologically plausible explanation for the behavioral effects of bilateral stimulation and possibly even EMDR. Moreover, it provides a foundation for future research into this enigmatic therapy. Given the growing need to offer effective treatment options to people with trauma-related conditions, this can indeed be considered an important development.

Another important study from 2019 was published in Molecular Psychiatry, a scientific journal published by Nature Publishing Group with a very high impact factor of 11.9. The researchers drew on studies showing methylated regions along certain DNA strands in patients with trauma-related conditions. Our DNA contains active and inactive regions. Molecules called methyl groups can be added to regions of DNA or to proteins, activating or inactivating a particular feature. Changes in gene regulation that occur in response to needs during life can be called epigenetic changes. For the first time, Vinkers and colleagues showed that EMDR could alter epigenetic patterns in patients with PTSD in differentially methylated regions, particularly regions associated with Zinc Finger Protein 57 (ZFP57). These findings provide evidence that methylation associated with these proteins plays a role in the development and successful treatment of PTSD. This is highlighted as an important step toward unraveling the interaction between psychological and biological systems by identifying genomic regions involved in the etiology and treatment of PTSD. In other words, much like a laboratory setting, EMDR therapy, which enables rapid recovery, offers a tremendous opportunity to examine the origins of disorders and the epigenetic changes that occur during recovery, and to understand the nature of improvement. It is truly impressive that the very features making EMDR therapy so interesting and intriguing may also help shed light on other unexplored areas.

## Conclusion

Once viewed as a mysterious treatment whose actions, like those of many psychotherapies, were poorly understood, EMDR therapy is now a very important therapeutic approach whose effectiveness in treating disorders is well established and whose mechanisms of action are increasingly being uncovered. Growing interest in this psychotherapy and recent research seem likely to shed light on other unknown aspects of our brains in the near future.

## References

- Lee, C. W., & Cuijpers, P. (2015). What does the data say about the importance of eye movement in EMDR?. Journal of behavior therapy and experimental psychiatry, 45(1), 226-228
- Amann, B. L., Fernandez, I., & Castelnuovo, G. (Eds.). (2019). Present and Future of EMDR in Clinical Psychology and Psychotherapy. Frontiers Media SA.
- Cantero, J. L., Atienza, M., Stickgold, R., & Hobson, J. A. (2002). Nightcap: a reliable system for determining sleep onset latency. Sleep, 25(2), 238-245.
- Holmes, A. (2019). Biological clues to an enigmatic treatment for traumatic stress.
- Kavakçı, Ö., Doğan, O., & Kuğu, N. (2010). EMDR (Göz hareketleri ile duyarsızlaştırma ve yeniden işleme): Psikoterapide farklı bir seçenek.
- Landin-Romero, R., Moreno-Alcazar, A., Pagani, M., & Amann, B. L. (2018). How does eye movement desensitization and reprocessing therapy work? A systematic review on suggested mechanisms of action. Frontiers in psychology, 9, 1395.
- Pearce, J. M., & Hall, G. (1980). A model for Pavlovian learning: variations in the effectiveness of conditioned but not of unconditioned stimuli. Psychological review, 87(6), 532.
- Shapiro, F. (2017). Eye movement desensitization and reprocessing (EMDR) therapy: Basic principles, protocols, and procedures. Guilford Publications.
- Vinkers, C. H., Geuze, E., van Rooij, S. J., Kennis, M., Schür, R. R., Nispeling, D. M.,... & Vermetten, E. (2019). Successful treatment of post-traumatic stress disorder reverses DNA methylation marks. Molecular psychiatry, 1-8.
- Yaşar, A. B., & Konuk, E. (2018). EMDR therapy. Klinik Psikofarmakoloji Bulteni, 28, 368-369.

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*This article was first published in the issue of Bilim ve Ütopya featuring EMDR as its cover topic (2020).*

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