How does EMDR work?

Eye Movement Desensitization and Reprocessing (EMDR) is a psychotherapeutic approach that has been particularly effective in treating trauma and post-traumatic stress disorder (PTSD).

EMDR is believed to affect the brain in several ways, particularly in how it processes and integrates traumatic memories. It involves the patient recalling distressing images while receiving one of several types of bilateral sensory input, such as side-to-side eye movements, hand tapping, or auditory tones. Here are some details of how researchers think EMDR can work:

Memory Processing and Integration: The theory underlying EMDR suggests that the bilateral stimulation (such as eye movements) somehow mimics the natural process of the rapid eye movement (REM) sleep phase, which is involved in the processing of emotional memories. During EMDR sessions, the bilateral stimulation is thought to facilitate the neurological processing of the traumatic memory. When a traumatic event occurs, it might be stored in an isolated memory network with intense emotion and physical sensations. EMDR appears to help the brain integrate these memories into general memory networks, thus reducing their emotional intensity.

1. Reduction in Emotional Response: EMDR seems to help decrease the vividness and emotion associated with traumatic memories. Several neuroimaging studies suggest that EMDR can reduce activation of the amygdala, which is heavily involved in emotional processing, particularly fear-related emotions. By doing so, it reduces the emotional response to the memories.

2. Increased Prefrontal Cortex Activity: Studies indicate that after EMDR therapy, there is increased activity in the prefrontal cortex, which is involved in managing attention, rational thought, and problem-solving. This might help individuals more effectively process and cope with traumatic memories.

3. Changes in Hippocampus: The hippocampus, a part of the brain crucial for memory storage and retrieval, is also affected. Traumatic stress can cause hippocampal volume to decrease, which might affect how memories are stored and retrieved. EMDR has been associated with normalization of hippocampal volume, which helps in properly storing and retrieving traumatic memories as non-threatening, thereby reducing symptoms of PTSD.

Although the exact mechanisms through which EMDR works are not fully understood, the therapeutic effects are well documented. More research is needed to clarify the neurological changes that occur and to better understand how these changes correlate with clinical improvements. However, the evidence thus far suggests that EMDR can be a powerful tool in modifying how traumatic memories are stored and processed in the brain.