How Does EMDR Therapy Work?
EMDR follows a structured sequence of phases. What's less settled is exactly why the bilateral stimulation at its centre helps, and it's worth being honest about that distinction.
The Structure of a Course of EMDR
Treatment moves through several stages: a thorough assessment of history and current symptoms; stabilisation, where grounding and emotional regulation strategies are built before any processing begins; the processing phase itself, where a specific memory is held in mind while bilateral stimulation is used; and integration, where new, more adaptive beliefs are consolidated once the memory has been reprocessed. None of these phases are skipped, regardless of how motivated someone is to get to the processing stage quickly: stabilisation in particular exists because processing before someone is ready can be destabilising rather than helpful.
What Happens During Processing
While recalling a specific distressing memory (an image, a thought, a body sensation connected to it), the client follows a form of bilateral stimulation, most commonly guided eye movements, though tapping or alternating auditory tones are also used. Short sets are followed by brief pauses to check in on what's coming up. Over repeated sets, most people notice the memory shifting: it starts to feel less vivid, less emotionally charged, more like something that happened rather than something still happening.
What's Established, and What's Still Debated
The evidence that EMDR is clinically effective for PTSD is well established: this is why NICE and the WHO recognise it as a treatment option. What's less settled is the precise mechanism behind why bilateral stimulation specifically contributes to that effect. Several theories exist (including ideas about how bilateral stimulation may affect working memory load, or parallels drawn with the eye movements that occur during REM sleep), but none of these mechanistic explanations has the same weight of evidence behind it as the treatment's clinical effectiveness itself. It's honest to say EMDR works for many people with PTSD, and separately honest to say the field hasn't settled on precisely why.
Why the Structure Matters
The phased structure isn't bureaucratic: assessment prevents processing being applied to the wrong presentation, stabilisation protects against processing before someone can tolerate it, and integration ensures a reprocessed memory settles into a more adaptive place rather than leaving the work half-finished. This is why EMDR delivered by a trained clinician looks quite different from the simplified versions sometimes described online.