How Does Eye Movement Desensitization and Reprocessing Therapy Work? A Systematic Review on Suggested Mechanisms of Action

Summary & key facts

EMDR is a proven therapy that helps many people with post-traumatic stress disorder, but scientists still do not agree on exactly how it works. The authors reviewed about 75 studies up to late 2017 and grouped explanations into three kinds: psychological ideas, body-based changes, and brain-based changes. They found reasonable evidence for one psychological idea called the working memory hypothesis and some evidence of body and brain changes after successful EMDR. However, the field is still young and bigger, better studies are needed before we can be sure what the key ingredients are.

Key facts:

• EMDR is considered an evidence-based and effective therapy for post-traumatic stress disorder.
• The authors reviewed about 75 studies published up to October 2017 that looked at how EMDR might work.
• The studies were sorted into three big models: psychological explanations, bodily or physiological explanations, and brain-based explanations.
• There is reasonable support for the working memory idea. This idea says that making eye movements while remembering a traumatic event uses up short-term memory and can make the memory feel less vivid and less upsetting.
• Researchers also found physical or physiological changes that were linked with successful EMDR therapy.
• New brain-imaging studies are starting to show possible changes in brain structure and activity before, during, and after EMDR, but these results are still preliminary.
• There is ongoing debate about whether the bilateral stimulation used in EMDR, like side-to-side eye movements, is an active part of how the therapy works.
• The review says the research is still in its early stages and calls for larger studies, clearer methods, and well-defined patient groups before firm conclusions can be drawn.

Abstract

Background: Eye movement desensitization and reprocessing [EMDR] is an innovative, evidence-based and effective psychotherapy for post-traumatic stress disorder [PTSD]. As with other psychotherapies, the effectiveness of EMDR contrasts with a limited knowledge of its underlying mechanism of action. In its relatively short life as a therapeutic option, EMDR has not been without controversy, in particular regarding the role of the bilateral stimulation as an active component of the therapy. The high prevalence of EMDR in clinical practice and the dramatic increase in EMDR research in recent years, with more than 26 randomized controlled trials published to date, highlight the need for a better understanding of its mechanism of action. Methods: We conducted a thorough systematic search of studies published until October 2017, using PubMed, ScienceDirect, Web of Knowledge and Scopus databases that examined the mechanism of action of EMDR or provided conclusions within the framework of current theoretical models of EMDR functioning. Results: Seventy-five studies were selected for review and classified into three overarching models; (i) psychological models (ii) psychophysiological models and (iii) neurobiological models. The evidence available from each study was analysed and discussed. Results demonstrated a reasonable empirical support for the working memory hypothesis and for the physiological changes associated with successful EMDR therapy. Recently, more sophisticated structural and functional neuroimaging studies using high resolution structural and temporal techniques are starting to provide preliminary evidence into the neuronal correlates before, during and after EMDR therapy. Discussion: Despite the increasing number of studies that published in recent years, the research into the mechanisms underlying EDMR therapy are still in its infancy. Studies in well-defined clinical and non-clinical populations, larger sample sizes and tighter methodological control are further needed in order to establish firm conclusions.

Topics

Anxiety, Depression, Psychometrics, Treatment, Cognitive Processes Posttraumatic Stress Disorder Research Traumatic Brain Injury Research

Categories

Clinical Psychology Psychology Social Sciences

Tags

Action (physics) Clinical psychology Desensitization (medicine) Epistemology Eye movement desensitization and reprocessing Internal medicine Mechanism (biology) Medicine Philosophy Physics Posttraumatic stress Psychology Psychotherapist Quantum mechanics Receptor

Conditions & symptoms

PTSD