Do the eye movements in EMDR actually do anything?

EMDR, eye movement desensitization and reprocessing, is a psychotherapy for post-traumatic stress disorder devised by Francine Shapiro in 1987. The person talks about traumatic memories while following side-to-side eye movements or another kind of bilateral stimulation, such as hand tapping. A session typically lasts 60 to 90 minutes, and the person recalls an image, a phrase and an emotion tied to a trigger while the stimulation runs. Unlike trauma-focused cognitive behavioural therapy, the WHO's 2013 guideline notes that EMDR does not involve detailed descriptions of the event, direct challenging of beliefs, extended exposure or homework.

Many official bodies recommend it, citing varying levels of evidence: the WHO, Britain's NICE, Australia's health research council and the US Departments of Veterans Affairs and Defense. The American Psychological Association does not endorse it as a first-line treatment, but says it is probably effective for adult PTSD.

The scientific argument is about why it works. Systematic analyses since 2013 generally indicate that EMDR works about as well as trauma-focused CBT for adults with PTSD, but most meta-analyses find that adding the eye movements makes little or no difference, though one 2013 meta-analysis with fewer exclusion criteria found a moderate effect, and meta-analyses also flag a high risk of allegiance bias in EMDR studies. On that reading its effect comes from the same methods other PTSD therapies use, exposure therapy and CBT techniques, and the distinctive add-on contributes nothing: a "purple hat therapy", as critics put it. Some critics go further and call EMDR a pseudoscience, because the theory and mechanism are non-falsifiable.

In 2022 the BBC correspondent Fergal Keane, who had PTSD, credited his EMDR therapist with helping save his life.