The Evidence Base for EMDR

How Does EMDR Work? – The Adaptive Information Processing Model

Francine Shapiro developed the Adaptive Information Processing Model to explain the therapeutic effects of EMDR. According to this model, when something challenging happens to us, we normally find a way to connect our challenging experience to our existing experiences, at both a conceptual and a neurological level. The connections we make provide us with useful learning for the future. You might think of this as how we develop wisdom.

For instance, if you have a conflict with a friend, you might reflect on the conflict for some time, talk to people about it, and perhaps even dream about it, until you come to a better understanding of the event. In doing this, you may develop a deeper understanding of yourself, your friend, or the situation, and eventually, as you allow your emotions to roll through you, and you manage to connect the conflict to your broader understanding of the world, you will no longer be disturbed by the event. The connections you make form knowledge and wisdom to guide you through your future interpersonal interactions.

If an experience is sufficiently disturbing, or you are never given the opportunity to reflect on it, then this normal, innate process of information processing may get stuck or may malfunction. In this case, the experience may get stored neurologically in an over-excitable, unprocessed, and disturbing state, making it easy to re-activate, and difficult to process when it is activated. This may lay the groundwork for post traumatic stress disorder. In some cases, this disturbing experience may be frequently re-activated in the form of intrusive thoughts, emotions or sensations, or in flashbacks and nightmares.


According to the Adaptive Information Processing Model (see above figure), disturbing events that have failed to link with other knowledge and wisdom stored in the brain can be adaptively linked with the help of dual attention. Dual attention refers to paying attention at once to both the disturbing event in the past and to some form sensory input (eye movements, hand tapping, auditory tones, etc...) that stimulates both hemispheres of the brain in the present. The scientific community is not entirely certain why stimulating both hemispheres of the brain helps to resolve troubling memories, but the research is clear that it does work when it is done with a properly trained therapist.

Some researchers think that having both of the brain's hemispheres being stimulated while thinking about difficult material helps the highly emotional right hemisphere make links with the rational and logical left hemisphere that were broken or poorly formed when an overwhelming experience occurred.

Other researchers think that the bilateral stimulation helps to keep people aware of the present moment when they mentally travel back into the troubling memories, and that this dual awareness of present and past helps people to stay relatively calm while remembering the troubling event, which allows their brains to resolve it with a calmer perspective.

Clinical observations by EMDR therapists suggest that once the brain's innate information processing system has been mobilised by the bilateral stimulation, the brain naturally moves you towards a healthy, integrated perspective of the event, in much the same way that the body as a whole moves towards health by automatically healing infections and injuries.

Is there a solid evidence base for EMDR?

Numerous studies have established that EMDR is an effective therapy for the treatment of post traumatic stress disorder. Research has typically compared EMDR to the other available evidence-based treatment, trauma-focused cognitive behavioural therapy.

It is worth noting that EMDR does not require participants to complete homework between processing sessions beyond making a note of any thoughts, memories or dreams that seem relevant to their processing, whereas the exposure phase of CBT requires 60-120 minutes of daily practice, with participants thinking about their trauma or being in the presence of triggers to their trauma for most of that time.

  • The Cochrane Database of Systematic Reviews (, which conducts meta-analyses of current literature, has concluded that EMDR and trauma-focused cognitive behavioural therapy are equally effective in the treatment of post-traumatic stress disorder.
    • Bisson, J., Roberts, N.P., Andrew, M., Cooper, R. & Lewis, C. (2013).  Psychological therapies for chronic post-traumatic stress disorder (PTSD) in adults (Review). Cochrane Database of Systematic Reviews 2013.

  • Several other meta-analyses have also shown EMDR to be an effective treatment for PTSD. An up-to-date list of recent meta-analyses may be viewed here:

Several international health and mental health organisations have endorsed EMDR as a treatment for PTSD, based on the accumulated clinical research that establishes its effectiveness. These include:

  • The World Health Organization (2013)
    • Guidelines for the Management of Conditions Specifically Related to Stress. Geneva, Switzerland: Author. Trauma-focused CBT and EMDR are the only psychotherapies recommended for children, adolescents and adults with PTSD.

  • The United Kingdom's National Institutes of Clinical Excellence (2005)
    • National Collaborating Centre for Mental Health (2005). Post traumatic stress disorder (PTSD): The management of adults and children in primary and secondary care. London: National Institute for Clinical Excellence.

  • The American Psychiatric Association (2004)
    • Practice Guideline for the Treatment of Patients with Acute Stress Disorder and Post-traumatic Stress Disorder. Arlington, VA: American Psychiatric Association Practice Guidelines. EMDR therapy was determined to be an effective treatment of trauma.

  • The International Society for Traumatic Stress Studies (2009)
    • Foa, E.B., Keane, T.M., Friedman, M.J., & Cohen, J.A. (2009). Effective treatments for PTSD: Practice Guidelines of the International Society for Traumatic Stress Studies New York: Guilford Press.

For a complete list of the international organisations who endorse EMDR as an effective treatment for PTSD, see here:

An up-to-date, searchable library of clinical research into EMDR is available at the Francine Shapiro Library:

More information about EMDR can be found in Francince Shapiro's book:

Shapiro, F (2001) Eye Movement Desensitization and Reprocessing (EMDR), Second Edition. UK: Guildford Press.