Eye Movement Desensitization and Reprocessing (EMDR) is a highly contentious psychotherapeutic modality. To some, it’s a saving grace. In fact, a recent CNA Insider documentary seemingly espoused the benefits of EMDR in the treatment of specific phobias. To others however, EMDR represents the many wrongs in the field of psychotherapy: pseudoscientific sham masked under layers of ‘scientific-sounding jargon’.
One common argument for the use of EMDR lies in the fact that it is listed under the American Psychological Association’s (APA) list of “research-supported treatments“. Surely a treatment endorsed by the APA can’t be wrong? However, if we accessed the APA’s page for EMDR, the following was indicated:
“The efficacy of EMDR for PTSD is an extremely controversial subject among researchers, as the available evidence can be interpreted in several ways. On one hand, studies have shown that EMDR produces greater reduction in PTSD symptoms compared to control groups receiving no treatment. On the other hand, the existing methodologically sound research comparing EMDR to exposure therapy without eye movements has found no difference in outcomes. Thus, it appears that while EMDR is effective, the mechanism of change may be exposure – and the eye movements may be an unnecessary addition. If EMDR is indeed simply exposure therapy with a superfluous addition, it brings to question whether the dissemination of EMDR is beneficial for patients and the field. However, proponents of EMDR insist that it is empirically supported and more efficient than traditional treatments for PTSD. In any case, more concrete, scientific evidence supporting the proposed mechanisms is necessary before the controversy surrounding EMDR will lift.“
Scrutinize further and we actually see that EMDR is not explicitly endorsed by the APA, but rather “Conditionally Recommended“. That is to say, stronger evidence exists for other therapeutic modalities, but while the existing research evidence for EMDR is not strong, there were some examples of positive outcomes using it.
So how then do we make sense of this enigmatic and controversial treatment? When reviewing evidence for treatment efficacy, meta-analyses and systematic review dominate the evidence hierarchy. As such, in today’s post, we will be discussing EMDR using a recent systematic review and meta-analysis.
Source: Cuijpers, P., van Veen, S. C., Sijbrandij, M., Yoder, W., & Cristea, I. A. (2020). Eye movement desensitization and reprocessing for mental health problems: a systematic review and meta-analysis. Cognitive Behaviour Therapy, 49(3), 165-180.
In order to fully appreciate the contentions behind EMDR (as well as make sense of the evidence that we will review), it is important to first understand what EMDR is.
Brief overview of EMDR & it’s controversies
According to Shapiro (the founder of EMDR, 2014), “EMDR therapy is guided by the adaptive information processing (AIP) model.” Accordingly, trauma (or other emotional dysfunction) are the outcomes of dysfunctional information processing. As a treatment modality, it comprises 8-phases from History-taking to Treatment Evaluation, of which bilateral stimulation in the form of eye-movements, sounds, or taps are utilized to help the brain reprocess traumatic memories in an adaptive manner, leading to recovery.
Now let us now look at some contentions. First, while the sentence “EMDR therapy is guided by the adaptive information processing (AIP) model” could give the impression that EMDR is a treatment guided by strong and independently established theoretical underpinnings, it was actually the reverse. “AIP theory was developed to explain the observed results of EMDR therapy delivered to individuals experiencing trauma and PTSD” (Hill, 2019). That is to say, the AIP model was theorized to explain the findings from early EMDR studies. Now that happens in science, where hypotheses and theories are proposed to explain a phenomenon, and subsequent experiments conducted support or reject the theoretical model. But that leads to a second issue, where the theoretical underpinnings of EMDR is largely unsupported by independent research in cognitive neuroscience. Simply put, findings from early EMDR studies led to the development of the AIP theoretical model, and the AIP model subsequently guides EMDR treatment. However, the AIP model is theoretically inconsistent with current understandings in cognitive neuroscience. If the AIP model is inaccurate, what then is EMDR guided by? How does EMDR work? Does EMDR even work? We will examine these questions below.
Does EMDR even work?
Cuijpers and colleagues (2020) included a total of 77 studies in their systematic review and meta-analysis. From their review,
- In treating post-traumatic stress disorder (PTSD), EMDR was superior to control (wait-list, treatment as usual). However, of the 27 studies included in this comparison, only 4 of 27 (14.8%) were rated ‘low risk of bias’. That is to say, in treating PTSD, doing EMDR was better than not doing anything. However, these findings were mostly based on highly biased studies.
- In treating PTSD, EMDR was ‘superior’* to other psychotherapies (e.g. Cognitive Behavioural Therapy, Prolonged Exposure). However, the vast majority of EMDR studies had a high risk of bias, and only 8 of 23 (34.8%) had a ‘low risk of bias’ rating. When examining only studies with low risk of bias, *there were no differences in outcomes between EMDR and other psychotherapies. That is to say, EMDR was better than other psychotherapies in treating PTSD only if we look at highly biased studies. When looking at studies with less bias, EMDR performed similar (not any better) to other psychotherapies.
- In treating anxiety disorders (specific phobias and test anxiety), EMDR was superior to control groups. However, 10 of 10 (100%) studies included in the analysis were rated ‘high risk of bias’. That is to say, in treating specific phobias and test anxiety, EMDR was better than not doing anything. However, these findings were obtained from studies that were of high risk of bias. There were no included studies that had a ‘low risk of bias’.
- There were insufficient studies to do a pooled analysis on the impact of EMDR in the treatment of other mental health conditions (e.g. depression, schizophrenia, bipolar, OCD etc.). That is to say, based on existing research, we do not know if EMDR is effective in treating conditions beyond PTSD and some anxiety disorders.
In short, EMDR works in treating PTSD and certain anxiety disorders compared to not doing anything. However, compared to other psychotherapies, EMDR performed comparably and was not superior to those other forms of treatment, especially when examining only studies with a low risk of bias.
How does EMDR work?
To answer this question, we would first need to understand the concept of dismantling studies. Unlike drug treatments where specific active ingredients could be isolated and tested, psychotherapies often involve an interplay of multiple factors, for example, therapist variables (how emphatic or skilled the therapist is), therapeutic alliance (which could be influenced by the gender or ethnicity of the therapist), client variables (readiness for treatment, motivation for change, past experience with psychotherapy), or specific treatment components of the therapeutic modality.
Dismantling studies aim to test the latter – the specific treatment components of a therapeutic modality – in order to identify the ‘active ingredients’ of each type of therapy that contributes to treatment outcomes. In these studies, full treatment therapies are compared against partial treatment therapies, where a specific component (usually the proposed ‘active ingredient’) is removed. Doing so allows the researcher to identify if the removed component has any therapeutic value in terms of treatment outcomes.
Back to EMDR, Cuijpers and colleagues (2020) included a total of 10 dismantling studies in their analysis. Only 2 of 10 studies (20.0%) had a low risk of bias. As eye movement/bilateral stimulation was theorized to be an essential component (‘active ingredient’) in the treatment (it’s even in the name, eye movement desensitization and reprocessing), 9 of 10 (90.0%) of the dismantling studies compared full EMDR to EMDR without eye movement.
- In the treatment of PTSD, there were no differences in outcomes between full EMDR, and EMDR without eye movement. That is to say, eye movements did not affect treatment outcomes and were likely not an essential component in the treatment of PTSD.
So what might the ‘active ingredient’ in EMDR be? Multiple scholars have proposed that the ‘exposure’ component is the key ingredient in EMDR. In fact, this was reflected in the APA’s statement on EMDR:
“Thus, it appears that while EMDR is effective, the mechanism of change may be exposure – and the eye movements may be an unnecessary addition. If EMDR is indeed simply exposure therapy with a superfluous addition, it brings to question whether the dissemination of EMDR is beneficial for patients and the field.“
Let us consider this: paracetamol is an active ingredient in pain relief. Paracetamol could be contained in tablet-form (with fillers), or perhaps in a syrup (sweetened).
A manufacturer could claim that their “special” tablet filler has healing properties. Another could claim that their syrup boosts pain relief over other products. In both situations, it works. The tablet or the syrup does indeed relief pain! But the active ingredient is the paracetamol content. The tablet filler or sweet syrup has no bearing on the treatment outcome (pain relief), except through placebo effect.
In this analogy, the eye movement/bilateral stimulation component of EMDR is akin to the tablet filler or the sweetened syrup. So, does EMDR work as a whole? Yes. Does it work according to it’s proposed mechanism/theory? Unlikely.
It gets more complicated
As noted by Cuijpers et al., (2020, p. 176), “there is quite some research on working mechanisms in EMDR, especially on the orienting response model and the limited capacity of the working memory. The original controversy on the effects of EMDR is therefore not solved, but the assumption that EMDR only works through the cognitive-behavioral elements seems to be too simple.”
Essentially, while the critics and opponents of EMDR are quick to relegate it’s active component to exposure therapy, until more high quality dismantling or additive component studies are done, the current controversy surrounding EMDR will not abate.
How might it affect you?
In so far, we’ve established that EMDR does work in treating PTSD and perhaps some anxiety disorders, especially when compared to doing nothing/treatment as usual care. Practically, does it affect end users of EMDR when seeking treatment? Perhaps not if we are examining treatment outcomes. Like in the paracetamol analogy, if you goal is pain relief, it might not matter as much if it comes in syrup or tablet form.
However, if finances are a concern, then such awareness would be important for clients to make informed decision. If EMDR treatment is significantly more costly than a different therapeutic modality (e.g. cognitive behavioural therapy [CBT], or prolonged exposure therapy), or vice versa, then perhaps it might be in your best interest to consider the option that is more financially appropriate, especially if they all contain the same active ingredient.
Additionally, there are benefits to having EMDR alongside other forms of therapy in the treatment of PTSD or anxiety. For example, a client who has had a poor experience with CBT may be more open to receiving the help they require through EMDR. Using the paracetamol analogy, individuals who struggle with swallowing tablets (e.g. children) may benefit from having paracetamol in syrup.
Also, while the eye movement/bilateral stimulation in EMDR may not affect treatment outcomes, it might make the treatment process more tolerable. As much as exposure is the active ingredient in trauma and anxiety treatments, the process of exposure is difficult. Studies have found the attrition (dropping out of treatment) rates in exposure therapy for PTSD to range between 24-33%! That is to say, a quarter to a third of therapy clients drop out of their treatment for PTSD. If bilateral stimulation, which may reduce the emotional intensity of the exposure process through attentional shifting/dual task interference, could reduce attrition rates, perhaps EMDR might take the win in that regard.
As a counter point however, perhaps attentional shifting/task interference could also be achieved through the use of other strategies unrelated to EMDR, such as progressive muscle relaxation (PMR)/relaxation strategies during exposure. In my own clinical practice, some of my clients have made tremendous progress through exposure therapy when a technique like PMR was first introduced at the start of the exposure treatment, and subsequently faded off after they have built their confidence in confronting their feared stimuli.
Alternatively, recent advances in the use of virtual reality in exposure therapy have also shown promising results with regards to attrition. A recent meta-analysis by Benbow and Anderson (2019) found that the drop out rates from 1057 participants were 16%!
Going back to our original questions. Does EMDR work? Yes, when treating PTSD and some anxiety disorders. How does EMDR work? While we’re uncertain of the exact mechanisms, the exposure component is likely a key active ingredient. Eye movements (and perhaps by extension bilateral stimulation) have been shown to contribute little to overall therapeutic outcomes. Coupled with the understanding of memories and information processing in cognitive neuroscience, this suggests that EMDR is theoretically unsound despite being somewhat efficacious. As more high quality studies are conducted, perhaps we might eventually better understand the theoretical underpinnings (or lack thereof) of EMDR.
As the late Professor Scott Lilienfeld (2011, p. 108) puts it,
“EMDR almost certainly fulfilled the EST [evidence-supported treatment] criteria for probable efficacy. Nevertheless, the skeptics were on to something. Although EMDR was indeed shown in several studies to be more efficacious than no treatment, there was no compelling or even especially suggestive evidence that the eye movements or other ostensibly theoretically distinctive features of the treatment mattered. Nor was there a shred of plausible evidence for the theoretical mechanisms (e.g., accelerated neural information processing) put forth for the treatment by EMDR’s developers. EMDR is theoretically dubious at best (many used far harsher language), skeptics groused; why should it be considered an EST?”
From a practical standpoint, as prospective seekers of psychotherapy, perhaps a key consideration would be the financial cost of seeking EMDR compared to other potential treatments.
Is EMDR science or pseudoscience? Perhaps the truth might lie somewhere in between.