Eye movement desensitization across subjects: subjective and physiological measures of treatment efficacy

Eye movement desensitization (EMD) was investigated in an experimental multiple baseline across subjects design. Six subjects who met the diagnostic criteria for Posttraumatic Stress Disorder (PTSD) were included in the study. While the EMD technique advanced by Shapiro has been reported to be clinically effective, major methodological issues have been raised which remain to be addressed. One issue raised is whether exposure to the traumatic image is sufficient to account for the reported clinical effects of EMD or whether the addition of saccadic eye movements is central to the treatment. This study attempted to address this concern by comparing two EMD-based procedures: a Non-saccade phase (without the saccadic eye movements) which functioned as a control and a second that included saccadic eye movements. Dependent variables included self-report information (SUDs, behavioral symptoms reports) and physiological data (heart rate and systolic blood pressure). The results showed no significant decreases in SUDs level with the EMD minus the saccadic eye movements procedure. However, five of the six subjects reported clinically significant decreases in their SUDs levels with the inclusion of the saccadic eye movements. This study appears to corroborate previous work employing single-case design as well as pre and postcomparisons.