Part 1: How does eye movement desensitisation and reprocessing (EMDR) work to combat trauma?

You may have heard about EMDR as a therapy for trauma and want to know more. If you have two days to spare, read Bessel Van der Kolk’s wonderful book ‘The body keeps the score’. It clearly and repeatedly makes the link between traumatic experiences, how we move through and deal with the memories of those events, or alternatively get stuck in them... and what we can do if we are stuck.

But if you only have 10 minutes, then read these two short articles which explain the theory of how EMDR uses neurological restructuring as the mechanism for change in therapy.

Part one of this article explains simply how post-traumatic stress affects our brain and body. Part two (http://www.counselling-directory.org.uk/counsellor-articles/part-2-how-does-eye-movement-desensitisation-and-reprocessing-emdr-work-to-comb) explains how EMDR may work to counter that mechanism.

Part one

What happens to us when we experience any stressful event and recover?

The main task of the brain is to ensure that we survive. Imagine you are faced with a threat, like a sabre tooth tiger approaching your campfire. A part of our brain called the thalamus brings together the sound of the tiger’s growls, the distance that the tiger is from you and other information from our senses into an integrated experience. It then sends two signals, one to the frontal cortex (the rational part of the brain) and one to the amygdala (the threat detection part that prepares the body for fight/flight or freeze. The amygdala decides whether to react, after checking with the hippocampus, which stores records of similar situations from the past. Then adrenaline is released to prepare the body to fight the tiger or flee or play dead. The amygdala receives the message fractions of a second before the frontal cortex, which can explain why you find yourself up the nearest tree without really knowing how you got there.

Once the threat is over the body returns to resting state and the experience begins to be processed and turned into a historical memory with place and date attached (like your digital photos), which then fades with time.

What happens to us when we experience a traumatic event that has lasting effects?

Sometimes, in the face of threat, the brain becomes overwhelmed to the extent that the reasoning part shuts down completely. When this happens the thalamus does not integrate the memory and it gets stored in discreet fragments which cannot be processed. Whenever these fragments get triggered, the traumatised person relives the experience with all the bodily felt sense of terror that goes with that. These memories remain as vivid as the day they happened and every time the memory is triggered the traumatised person is then left trying to manage the physical effects of this adrenaline overload.

Usually what happens is that over time, the trauma gets processed eventually. Sometimes life provides the information that we need to move on from a trauma. A car accident that leaves someone thinking "I will never recover, I am defunct" may be replayed until the trip to the hospital where he is told that he will make a full recovery, when the traumatic event can move into the background. The death of a parent may leave the client feeling both anxious and devastated and with the thought "I am alone", until other relationships begin to fill the space. But sometimes the brain has been so overwhelmed by the event that thoughts about it just lead to feeling overwhelmed again, which prevents the terrifying thoughts that go with the memory from being challenged. 

So, after you have been attacked by a tiger, the sight of a tiger pattern may trigger the thought "this tiger will eat me and I am going to die" and if the adrenaline released in response to this trigger overwhelms the brain, the thought that you are going to die cannot be challenged by the knowledge that you survived.

In the long term, the rushes of adrenaline that occur whenever the memory is triggered lead to hyper-vigilance, avoidance of certain situations, anxiety and exhaustion due to being in a constant state of high alert. The body is remembering what the brain can’t and this is called post-traumatic stress.

When trauma is stored in this physical way, therapies that help us to pay attention to and befriend what is going on in our bodies e.g. acupuncture, EMDR, yoga and massage (the four most accessed treatments by survivors of the world trade centre attacks) are far more effective than those which engage the adult thinking rational brain – cognitive behavioural therapy, mindfulness and psychoanalysis. Just talking about the trauma can reactivate it and lead to re-traumatisation, so an approach that engages the body is far safer and more effective.

To find out how EMDR works to release the trauma read the second part of this article (http://www.counselling-directory.org.uk/counsellor-articles/part-2-how-does-eye-movement-desensitisation-and-reprocessing-emdr-work-to-comb).