How does EMDR work?

Traumatic memories are thought to be stored in a different part of the brain from processed memories (the amygdala rather than the hippocampus).  This is important because whilst the hippocampus is involved in memory forming, organising, and storing long-term memories, the amygdala attaches strong emotional significance to memories, but is unable to store when or where a memory occurred. This means that whenever a memory in the amygdala is triggered, it feels as though it is a current threat and activates the body’s fight or flight system. Because these traumatic memories have not been appropriately ‘filed away’ in the brain, they will not be connected to other adaptive memories, learning or beliefs, but be linked only to the distressing thoughts and emotions that were present at the time of the trauma.  EMDR aims to reprocess these traumatic memories, moving them within the brain so that they have less emotional impact.

The main aim of EMDR is to ‘unstick’ or ‘reprocess’ the traumatic memories, and move them to a part of the brain that is able to recognise these events as being in the past and can connect them with more helpful and adaptive ways of thinking.  These memories are not forgotten, but the person is able to recognise them as being ‘old memories’ that do not evoke the same level of distress. It also helps to desensitise the person to the emotional impact of the memory, so that they can think about the event without experiencing the same intense level of emotion.  Additionally EMDR aims to change the meaning of the event for the person, so that its emotional impact is altered.  For example ‘It was not my fault’, ‘I am safe now’, ‘I am ok’, ‘I did my best’, rather than a more distressing view of the event.

Initial stages of EMDR involve ‘resource building’, helping you to increase your tolerance for the processing stage of the therapy.  The processing, or ‘desensitization’ phase involves evoking a ‘dual awareness state’ i.e. maintaining awareness of present moment experiences (achieved through bilateral rapid eye movements, taps or sounds) while simultaneously recalling memories of the traumatic event. This is a state referred to as Dual Attention Stimulation (DAS).

There is a lot of research demonstrating the effectiveness of EMDR therapy. There have been several hypothesized reasons for why EMDR is so effective. However, whilst we understand more now about the various mechanisms that are likely to result in EMDR being an effective treatment, we still do not fully understand why it is so effective.