Can working memory account for EMDR efficacy in PTSD?

Summary & key facts

Researchers looked at whether the benefit of EMDR for PTSD can be explained by a 'working memory' idea: if you try to hold a traumatic memory while doing a second task, your limited mental space can't fully hold the memory, so it becomes less vivid and less emotional. They reviewed 11 studies and found that, across different designs, adding a secondary task during recall made traumatic memories feel less vivid and upsetting than just remembering alone. Some studies showed this change might not last long, so the idea looks promising but not yet proven as a full explanation.

Key facts:

• EMDR (a therapy that often uses back-and-forth eye movements) helps many people with PTSD, but scientists do not fully agree on why it works.
• The authors followed established review rules and examined 11 studies that tested the same basic idea in different ways.
• The review included studies with people who had PTSD symptoms and studies with people who did not have a PTSD diagnosis.
• Across the studies, asking someone to recall a traumatic memory while doing a second task reduced how vivid the memory felt.
• Across the studies, doing a second task while recalling also made the memory feel less emotional or upsetting than recalling alone.
• Two studies that checked later on suggested the reduction in vividness and emotional upset might not last for a long time.
• These results support the 'working memory' idea: doing two things at once uses up limited mental space and seems to weaken how strongly a memory is experienced.
• The review does not prove this is the only reason EMDR can help. More research is needed, especially to know how long the effects last and how this links to long-term symptoms.

Abstract

BACKGROUND: Although eye movement desensitization and reprocessing (EMDR) has been shown to be effective in the treatment of PTSD for years, it remains controversial due to the lack of understanding of its mechanisms of action. We examined whether the working memory (WM) hypothesis -the competition for limited WM resources induced by the dual task attenuates the vividness and emotionality of the traumatic memory - would provide an explanation for the beneficial effect induced by bilateral stimulation. METHODS: We followed the Prisma guidelines and identified 11 articles categorized in two types of designs: studies involving participants with current PTSD symptoms and participants without PTSD diagnosis. RESULTS: Regardless of the types of studies, the results showed a reduction of vividness and emotionality in the recall of traumatic stimuli under a dual-task condition compared to a control condition, such as recall alone. However, two studies used a follow-up test to show that this effect does not seem to last long. CONCLUSION: Our results provide evidence for the WM hypothesis and suggest that recalling a traumatic memory while performing a secondary task would shift the individual's attention away from the retrieval process and result in a reduction in vividness and emotionality, also associated with the reduction of symptoms.

Topics

Child Abuse and Trauma Mind wandering and attention Posttraumatic Stress Disorder Research

Categories

Clinical Psychology Psychology Social Sciences

Tags

Clinical psychology Cognition Cognitive psychology Developmental psychology Economics Emotionality Eye movement desensitization and reprocessing Management Neuroscience Posttraumatic stress Psychology Recall Task (project management) Traumatic memories Working memory

Conditions & symptoms

PTSD Anxiety or worry