EMDR (Eye Movement Desensitization and Reprocessing) therapy is a structured approach to treating trauma in which you recall distressing memories while following a form of side-to-side stimulation, typically guided eye movements. Sessions usually last up to 90 minutes, are held weekly, and span roughly three months. The process follows eight distinct phases, though the core of the work happens during a few intense reprocessing phases where the goal is to change how your brain stores painful memories.
The Theory Behind It
EMDR is built on the idea that trauma disrupts the brain’s normal ability to process and file away experiences. Instead of being stored like other memories, traumatic events get stuck in their raw, unprocessed form, complete with the original images, emotions, and body sensations. This is why a sound, a smell, or a situation can pull you right back into a traumatic moment as if it’s happening now.
The therapy aims to restart that stalled processing. By activating the memory while simultaneously engaging in bilateral stimulation (something that moves your attention back and forth between the left and right sides of your body), the brain appears to shift how the memory is stored. Animal research has found that this type of stimulation can protect brain cells in the hippocampus, a region critical for memory, from the structural damage caused by stress. The end result for patients is that the memory remains but loses its emotional charge.
The Eight Phases
EMDR follows a standardized eight-phase protocol. Not every phase happens in every session, and some phases may take multiple sessions to complete.
Phase 1: History and treatment planning. You and your therapist discuss what brought you to therapy, your history, and which memories or experiences are most distressing. Together, you identify the specific events that will become targets for reprocessing. For straightforward trauma, like a car accident, there may be an obvious memory to address. For people with a long history of difficult experiences, especially in relationships, the therapist may need to sort through many memories or start with a pervasive feeling (like chronic loneliness or a sense of being unsafe) rather than a single event.
Phase 2: Preparation. Your therapist explains how EMDR works and teaches you specific techniques for managing emotional distress, both during sessions and between them. This phase builds a sense of safety and trust. Some people spend considerable time here before moving forward, particularly if their trauma history is complex.
Phase 3: Assessment. You identify the specific target memory, including the image that represents the worst part of it, the negative belief you hold about yourself because of it (such as “I’m not safe” or “It was my fault”), and the positive belief you’d like to hold instead. You rate how disturbing the memory feels on a 0-to-10 scale and how true the positive belief feels on a 1-to-7 scale. These ratings give you and your therapist a baseline to measure progress.
Phases 4, 5, and 6: Reprocessing. These are the active core of EMDR and all involve bilateral stimulation. This is where the session looks and feels most different from traditional talk therapy.
Phase 7: Closure. Every reprocessing session ends with your therapist guiding you back to a calm, grounded state, whether or not the processing of a particular memory is complete.
Phase 8: Reevaluation. Each new session after reprocessing begins by checking in on previously processed memories. You and your therapist confirm that the distress has stayed low and the positive belief still feels solid, then decide what to target next.
What the Reprocessing Phases Feel Like
Phases 4 through 6 are where most people’s curiosity (and anxiety) centers. During desensitization, your therapist asks you to hold the target memory in mind, along with the negative belief and any body sensations connected to it, while following a form of bilateral stimulation. The most common method is tracking the therapist’s fingers as they move back and forth in front of your face. Some therapists use handheld buzzers that vibrate alternately in each hand or tones that alternate between your left and right ears through headphones.
Each set of stimulation lasts about 20 to 30 seconds. Afterward, the therapist pauses briefly and asks what came up: a new image, a thought, a feeling, a physical sensation. You report whatever surfaced, then your therapist guides you into the next set. You don’t need to narrate the memory in detail. The therapist is not analyzing or interpreting your experience. Their role is to keep the process moving.
During this phase, your mind may jump from the original memory to related memories, emotions, or physical sensations. This is expected and is actually a sign that processing is working. Some people experience strong emotions like sadness, anger, or fear. Others notice the memory becoming less vivid or more distant, like watching it on a screen rather than being inside it. The desensitization phase continues until the memory no longer causes distress when you bring it to mind.
In the installation phase, the therapist helps strengthen the positive belief you identified earlier (“I am safe,” “I did the best I could”) by pairing it with bilateral stimulation until it feels genuinely true. During the body scan, you mentally scan your body while thinking about the memory and the positive belief. If any tension, tightness, or discomfort remains, it gets targeted with additional sets of stimulation until your body feels clear.
Reprocessing of a single memory is considered complete when the distress rating drops to zero, the positive belief feels completely true, and your body is free of any related physical tension.
What to Expect After a Session
Many people experience what’s sometimes called an “EMDR hangover” in the hours or days following a reprocessing session. This is temporary and reflects the brain continuing to process material that was activated during the session.
Emotionally, you may feel heightened sensitivity, unexpected mood shifts, or a sense of being emotionally raw. Some people feel unusually tired or temporarily numb. Physically, fatigue is extremely common since the brain uses significant energy during reprocessing. Headaches, muscle tension, sleep changes, and shifts in appetite can also occur. Cognitively, many people describe brain fog, difficulty concentrating, or having unexpected memories surface between sessions. These effects typically last anywhere from a few hours to several days and tend to diminish as therapy progresses.
Your therapist will have taught you grounding and coping techniques during the preparation phase specifically for managing this window. Keeping your schedule lighter after sessions, when possible, is a practical step many people find helpful.
How Effective It Is
EMDR has strong evidence behind it for PTSD specifically. In one widely cited study, 17 out of 20 participants no longer met the criteria for a PTSD diagnosis within 12 to 15 weeks of treatment. At a six-month follow-up, none of the 20 still qualified for the diagnosis.
The World Health Organization and the American Psychological Association both recommend EMDR for PTSD treatment. The APA classifies it as a conditionally recommended second-line treatment, placing it just behind cognitive behavioral therapy, cognitive processing therapy, and prolonged exposure therapy, which are strongly recommended as first-line options. In practice, the choice between these approaches often comes down to patient preference and therapist expertise, since all have solid evidence behind them.
Who It Works Best For
EMDR was originally developed for PTSD and that remains its strongest evidence base. It’s most straightforward when there’s a clear link between symptoms and a specific traumatic event, such as an assault, an accident, or a natural disaster.
For people with complex or relational trauma, where the damage comes from repeated experiences over years rather than a single event, EMDR can still be effective but often requires more time in the early phases and a more flexible approach to choosing targets. Some therapists work “bottom-up,” starting from a feeling or body sensation rather than a specific memory, which can be especially useful for people who struggle to identify individual events but carry a persistent sense of threat or unworthiness.
EMDR is increasingly used beyond PTSD for conditions like anxiety, phobias, grief, and chronic pain, though the research base for these applications is still developing compared to the robust evidence for trauma.