How Does EMDR Work?

TraumaEMDRPTSD

Aug 30

We get this question all of the time! If you have ever heard of EMDR (Eye Movement Desensitization and Reprocessing), you may have wondered: how can moving your eyes back and forth while recalling a memory help with trauma? It almost sounds too simple to be effective. Yet EMDR has been studied for more than 30 years, and research consistently shows it helps people recover from posttraumatic stress disorder (PTSD) and other trauma-related symptoms (Shapiro, 1989; Bisson et al., 2013). The mystery is less about if it works and more about how.

The Part We Know for Sure

What is clear is that EMDR changes the way traumatic memories are stored in the brain. When a traumatic event occurs, your amygdala—the brain’s built-in threat detector—often becomes hypersensitive. It keeps the body in constant overdrive, triggering intense emotional reactions even when there’s no present danger. Meanwhile, the hippocampus, which helps organize memories, struggles to properly encode these experiences, leaving memories unprocessed and emotionally raw.

Trauma often leaves memories feeling “stuck,” vivid, raw, and easily re-triggered as if the event is happening right now. During EMDR, clients recall these distressing memories while engaging in a form of bilateral stimulation (usually guided eye movements, but sometimes taps or tones). Over repeated sets, the memory becomes less emotionally intense and easier to integrate into a person’s life story (Shapiro, 2001; van den Hout & Engelhard, 2012).

Shapiro’s Adaptive Information Processing Model

Francine Shapiro, the founder of EMDR, proposed that psychological distress often comes from memories being stored in a dysfunctional form. They are essentially “frozen in time” with the emotions, body sensations, and negative beliefs experienced during the trauma. Because these memories are inadequately processed, they continue to cause symptoms in the present. EMDR works by activating these stuck memory networks while stimulating the brain’s natural processing system. EMDR also activates the prefrontal cortex, allowing the brain to reevaluate and integrate traumatic experiences. The event is still remembered, but it no longer feels like it is happening now. In Shapiro’s words, EMDR helps transform traumatic experiences into “just another memory” (Shapiro, 2001).

Other Theories

Scientists have also tried to explain how the eye movements and other forms of bilateral stimulation contribute to this reprocessing:

Working Memory Theory: Focusing on a traumatic memory and tracking eye movements taxes the brain’s working memory. This reduces the vividness and emotional intensity of the memory (van den Hout & Engelhard, 2012).
REM Sleep Analogy: Some researchers believe that EMDR mimics the process that occurs during REM sleep, when the brain integrates and processes emotionally charged experiences (Stickgold, 2002).
Dual Attention / Orienting Response: Alternating stimulation helps people stay grounded in the present while revisiting the past. This makes it safer to process overwhelming material (Lee & Cuijpers, 2013).

These theories complement Shapiro’s model. They attempt to explain why the brain can reprocess memories once they are activated.

Other Effects

Even though researchers are still debating exactly how EMDR works, the evidence that it does work is strong. Dozens of randomized controlled trials and multiple meta-analyses have shown EMDR to be effective. The World Health Organization, the American Psychiatric Association, and the U.S. Department of Veterans Affairs all list EMDR as a frontline treatment for trauma. Some other key takeaways:

EMDR Lowers The Amygdala “Alarm”
EMDR eye movements result is less activity in the right amygdala and in its connection with another emotional area (rostral anterior cingulate cortex). EMDR helped the brain’s “danger detector” get less twitchy. Researchers observed a decrease in “noise” in emotional brain centers and a shift toward brain activity typically associated with calmness and reflection.(ResearchGate – Pagani et al. 2012)
EMDR Helps Fear Memory Fade
People become better at not reacting with fear automatically—meaning they feel safer within themselves. After treatment, participants showed improved ability to “unlearn” fear. Their brain scans also revealed reduced activity in areas tied to fear and emotional processing (like parts of the amygdala, prefrontal cortex, and hippocampus). EMDR doesn’t erase the memory. It quiets and fades it. In our experience, clients have described the memory as blurred, black and white, or far away. (Rousseau, P-F., et al., 2019)

Putting It All Together—What It Means

Importantly, EMDR is not limited to single-event trauma. It has been adapted successfully for people with complex PTSD, where there are multiple, repeated, or developmental traumas that can make healing especially challenging (Valiente-Gómez et al., 2017). Emerging evidence also suggests EMDR can help with other conditions where unprocessed memories and anxiety loops play a role, such as panic disorder, phobias, and generalized anxiety (de Jongh et al., 2019).

So while scientists continue to study the finer details of why EMDR works, the clinical reality is clear: it consistently helps people process trauma and reclaim their lives. Whether explained through Shapiro’s Adaptive Information Processing model, working-memory effects, or a mix of mechanisms, the outcome is what matters most. Distressing memories lose their grip, and people move forward with less fear and more freedom.

If you are interested in learning more about EMDR, reach out to us at this link to speak to an EMDR specialist.

References

Bisson, J. I., Roberts, N. P., Andrew, M., Cooper, R., & Lewis, C. (2013). Psychological therapies for chronic post-traumatic stress disorder (PTSD) in adults. Cochrane Database of Systematic Reviews, 2013(12), CD003388. https://doi.org/10.1002/14651858.CD003388.pub4
de Jongh, A., Amann, B. L., Hofmann, A., Farrell, D., & Lee, C. W. (2019). The status of EMDR therapy in the treatment of posttraumatic stress disorder 30 years after its introduction. Journal of EMDR Practice and Research, 13(4), 261–269. https://doi.org/10.1891/EMDR-D-19-00029
Lee, C. W., & Cuijpers, P. (2013). A meta-analysis of the contribution of eye movements in processing emotional memories. Journal of Behavior Therapy and Experimental Psychiatry, 44(2), 231–239. https://doi.org/10.1016/j.jbtep.2012.11.001
Pagani, M., Di Lorenzo, G., Verardo, A. R., Nicolais, G., Monaco, L., Lauretti, G., Russo, R., Niolu, C., Ammaniti, M., Fernandez, I., & Siracusano, A. (2012). Neurobiological correlates of EMDR monitoring – An EEG study. PLOS ONE, 7(9), e45753. https://doi.org/10.1371/journal.pone.0045753
Rousseau, P.-F., El Khoury‑Malhame, M., Reynaud, E., Boukezzi, S., Cancel, A., Zendjidjian, X., Guyon, V., Samuelian, J. C., Guedj, E., Chaminade, T., & Khalfa, S. (2019). Fear extinction learning improvement in PTSD after EMDR therapy: An fMRI study. European Journal of Psychotraumatology, 10(1), Article 1568132. https://doi.org/10.1080/20008198.2019.1568132
Shapiro, F. (1989). Eye movement desensitization: A new treatment for post-traumatic stress disorder. Journal of Behavior Therapy and Experimental Psychiatry, 20(3), 211–217. https://doi.org/10.1016/0005-7916(89)90025-6
Shapiro, F. (2001). Eye movement desensitization and reprocessing: Basic principles, protocols, and procedures (2nd ed.). Guilford Press.
Stickgold, R. (2002). EMDR: A putative neurobiological mechanism of action. Journal of Clinical Psychology, 58(1), 61–75. https://doi.org/10.1002/jclp.1129
Valiente-Gómez, A., Moreno-Alcázar, A., Treen, D., Cedrón, C., Colom, F., Pérez, V., & Amann, B. L. (2017). EMDR beyond PTSD: A systematic literature review. Frontiers in Psychology, 8, 1668. https://doi.org/10.3389/fpsyg.2017.01668
van den Hout, M. A., & Engelhard, I. M. (2012). How does EMDR work? Journal of Experimental Psychopathology, 3(5), 724–738. https://doi.org/10.5127/jep.028212