EMDR: Examining the possible 24 hour long-term effect of eye movements with negative psychical and psychological integrity life events as a potential predictor

An effective treatment for posttraumatic stress disorder is eye movement desensitization and reprocessing (EMDR). The explanation of the efficacy is captured in the working memory (WM) theory. Both eye movements (EM) and recalling an aversive memory demand cognitive load of the WM and this competition for the capacity reduces the vividness and emotionality. This present study further examines EM with the long-term efficacy and type of trauma as a possible predictor for efficacy. We hypothesized that 1) there is a larger decrease of vividness, unpleasantness and subjective unit of distress for EM from pre-test to post-test compared to recall only (RO) and 2) this decrease lasts after 24 hours and 3) at the post-test and follow-up, physical integrity threats will be showing a larger decrease for EM than psychological integrity threats (i.e., memories categorized based on physical and psychological elements such as general treat or self esteem). Beforehand, 70 participants were randomly assigned to the experiment group (EM) or the control group (RO). For the intervention, participants chose two memories, one becoming the main memory and the other was used as the filler memory. Afterwards this target image was being divided into the type of trauma, based on the division of the previous research. We measured the self-reported vividness, unpleasantness and subjective unit of distress before, continually throughout (each 4 x 24s) and after (32 x 24s) the intervention and after 24 hours. EM and RO both showed a decrease in vividness, unpleasantness and subjective unit of distress. After 24 hours there was a return of distress for EM, whereas RO was still decreasing. Overall, with a significant lower score at the follow-up, both conditions remained effective over time. Type of trauma did not show any difference in outcome. This study found support for the 24 hour effect of EM and RO, however there was no additive effect for EM. Furthermore, based on this study, type of trauma cannot be used as a predictor for the efficacy of EM.

Dissertation/Thesis

English

M. Poortman

Poortman, M. (2017). EMDR: Examining the possible 24 hour long-term effect of eye movements with negative psychical and psychological integrity life events as a potential predictor. (Master's thesis, Utrecht University)