EMDR Therapy Side Effects

EMDR is often sold as gentle. You do not have to describe the event in detail. You do not have to write a trauma narrative and read it aloud. There is no homework. Compared with sitting in a room recounting the worst thing that ever happened to you, week after week, it can look like the soft option.

It is not the soft option. It is a different option.

EMDR therapy is a powerful procedure, and powerful procedures have effects. Some of them are unpleasant. A few of them, in the wrong hands and with the wrong client, are dangerous. You are entitled to know that before you start rather than discover it at eleven o'clock on a Tuesday night.

The three common ones

Tal Croitoru, writing a guide for clients rather than clinicians, names three side effects of EMDR. It is a short list, and it is worth knowing it.

Tiredness during or straight after the session. This is the commonest by a distance. It does not always happen. It is the natural consequence of a process that has been running your emotions, your senses, your thinking and your body at once for the best part of an hour. People describe it as being flattened. It generally passes within a day.

A rise in distress before the fall. Processing a single event usually takes between one and three sessions. If the memory has not been fully processed by the time the session ends, it may keep pressing on you until the next one: more intrusive thoughts, more dreams about the event. Croitoru's own answer to this is practical. For serious material he suggests booking a double session, or more than one session that week, so the gap where the unfinished processing sits is as short as possible.

Acting out in the present. The rarest of the three, and he says he has only seen it a handful of times. The material becomes intense enough that the person loses track of whether the feeling belongs to then or to now, and behaves as though it belongs to now. Getting up and walking out of the room, for example.

That is the honest short list for most people having EMDR for a single, discrete trauma.

Abreaction, and why it does not mean something has gone wrong

The word you may hear, and which sounds alarming, is abreaction. Rotem Brayer defines it as the discharge of affect that happens when material that has been kept out of consciousness comes back into it. Some people abreact somatically, with strong physical sensations. Others abreact with intense emotion.

You are being asked to notice the same feelings and body sensations you had during the worst part of the event. It should not be a surprise that the feelings and sensations turn up.

Brayer's point is that whether abreaction is frightening or bearable depends almost entirely on preparation. If you have not been told it might happen, it is terrifying and it feels like a collapse. If you have been told, and you understand it as a normal part of the road rather than a derailment, it is survivable.

So an intense emotional discharge in an EMDR session is not, by itself, a side effect that means the treatment is harming you. It is often the treatment working. What matters is whether you can be brought back down before you leave the room, and that is the therapist's job.

Where the real risk sits

Now the part that gets skated over.

Shapiro was blunt about this in her own textbook. Of all the reports she received from clinicians over the years about EMDR causing problems and potential harm, the ones that came up most frequently by a long way involved clients with dissociative disorders.

Her position is not that EMDR cannot help these clients. Clinicians trained to work with this population report that it accelerates the work considerably. Her position is that no clinician should use EMDR with a dissociative client unless they have training and experience with that population, are skilled in cognitive interweave, and understand the strategies for managing intense affect during processing. The potential for harm, she wrote, is great if EMDR reprocessing is used inappropriately or recklessly. Inadequate screening, inadequate preparation or careless implementation can be significantly destabilising.

Croitoru says something similar from the client side. Where there is significant dissociation, parts of the personality are split from one another, and standard EMDR may only reach one part. Applied without adaptation, it can make things worse.

Sit with that for a second. The most serious side effect of EMDR is not tiredness or a bad dream. It is destabilisation in a person whose system was holding itself together by keeping things apart.

The EMDR Dissociative Disorders Task Force guidance, reproduced in Shapiro's appendices, lists signs that tend to contraindicate EMDR reprocessing. Among them: ongoing self-harm, active suicidal or homicidal intent, uncontrolled flashbacks, rapid switching, extreme age or physical frailty, terminal illness, a need for concurrent medication adjustment, an ongoing abusive relationship, and active substance misuse.

These are not absolute bars in every case. The guidance is careful about that. But the risks stack up, the benefit has to clearly outweigh them, and only therapists with real experience of managing those complications should be proceeding at all.

If you are living in an ongoing abusive situation, this is worth reading twice. The trauma is not in the past. Processing it as though it were is not a neutral act.

The physical cautions

There are a few, and they are mostly small, but they exist.

Epilepsy and neurological impairment. Shapiro reports having heard of three clients who had seizures during EMDR processing sessions, all small. Two occurred with eye movements, one with a light bar. That is a very low number across an enormous amount of clinical use, and people with epilepsy have been treated successfully with EMDR. But if you have epilepsy, or any history of neurological abnormality or organic brain injury, your therapist should know before you start, and medical consultation should be sought if there is any doubt. Tactile or auditory bilateral stimulation exists precisely so that eye movements are not the only route.

Medication. No medication appears to block EMDR processing entirely. Benzodiazepines, however, have been reported to reduce treatment efficacy in some clients. There is also an odd effect worth knowing about: clinicians have reported that when a memory processed while the client was medicated is revisited after the medication stops, it can come back carrying roughly half its original disturbance. A memory that went from a 10 to a 0 on medication might rate a 5 once the medication has gone. It suggests the processing was, in part, state dependent. It does not mean you should stop your medication. It means your therapist needs to know what you are taking, and may need to revisit targets later.

Alcohol and substances. Someone in severe or chronic alcohol dependence, needing detox, at risk of seizures or in poor physical health needs a higher level of care and medical supervision, not a course of EMDR.

The side effect that is really a treatment failure

There is one more, and it is the one I most want you to notice, because it is the one you can do something about.

Leaving a session unregulated.

Brayer is unambiguous. You do not end an EMDR session while the client is at a level of disturbance they cannot bring down. Doing so can lead to rapid deterioration, and he names what that can look like: suicidal thoughts, risky or unhealthy behaviour, psychiatric hospitalisation. It is, he says, the difference between an unpleasant evening and a visit to A&E.

Phase 7 of the EMDR protocol, closure, exists for exactly this reason. Every session should leave real time at the end to bring you back into a regulated state. Calm place, container exercise, grounding, breathing, whatever it is that actually works for you. You should leave feeling contained. Not necessarily cheerful. Contained.

And before you ever begin processing, you should have a plan for the bad night. What will you do if the disturbance becomes overwhelming? Who will you call?

If you are regularly leaving EMDR sessions in pieces with no plan and no closure, that is not a side effect of EMDR. That is a failure of delivery, and it is worth raising, and if it does not change, it is worth changing therapist.

What none of this means

None of this means EMDR is dangerous. NICE recommends it. The WHO recommends it. Millions of people have had it without incident, and the ordinary experience is a hard hour, a tired evening, a strange dream, and then a memory that no longer takes the air out of the room.

What it means is that "gentle" was always the wrong word, and that the safety of EMDR sits almost entirely in the preparation. In phase 1 and phase 2, before any bilateral stimulation happens at all, your therapist is supposed to take a full history, screen for dissociation, check that you can actually regulate yourself, and build the skills you will need. Those phases are not throat-clearing before the real work. They are the reason the real work is safe.

The therapists who cause harm with EMDR are not, generally, the ones who did the protocol badly. They are the ones who skipped the first two phases and went straight to the eye movements, because that is the exciting bit.

Ask your therapist what their training is. Ask what happens if you become overwhelmed. Ask what the plan is for the week after.

A good EMDR therapist will be pleased you asked.

This is general information, not clinical advice. If you are considering EMDR, discuss your history and any medical conditions with your therapist and your GP. If you are in crisis, contact your GP, NHS 111, or Samaritans on 116 123.

References

Brayer, R. (2023). The Art and Science of EMDR: Helping Clinicians Bridge the Gap. PESI Publishing.

Croitoru, T. (2014). The EMDR Revolution: Change Your Life One Memory at a Time. Morgan James Publishing.

Shapiro, F. (2017). Eye Movement Desensitization and Reprocessing (EMDR) Therapy: Basic Principles, Protocols, and Procedures (3rd ed.). Guilford Press.