The Use of a Pressure Vest to Reduce Anxiety and Dissociation during Eye Movement Desensitization and Reprocessing—A Single-Case Experimental Design Study

Eye movement desensitization and reprocessing (EMDR) is an effective treatment for post-traumatic stress disorder, but dropout rates are high because the treatment can be overwhelming. This study investigated the hypothesis that the use of a pressure vest would decrease anxiety and dissociation during EMDR. Eight adult patients with post-traumatic stress disorder after complex interpersonal trauma were treated with EMDR in an outpatient psychiatric clinic. A single-case experimental design with randomized block design was used, randomly alternating EMDR treatment sessions with and without a pressure vest. After a baseline assessment, patients underwent EMDR weekly for 6 weeks, followed by a postmeasurement. Three patients followed all 6 sessions of EMDR; the other patients prematurely dropped out of the study. Visual, descriptive, and inferential analyses showed evidence neither for less anxiety and dissociation nor for a faster decrease in subjective units of distress in sessions with versus without a pressure vest. Descriptive and inferential analyses even suggested that patients experienced more anxiety with a pressure vest. However, all patients but one spent more time in actual EMDR treatment in sessions with a pressure vest than in sessions without a pressure vest. Patients and therapists reported that the pressure vest contributed to feeling safe, which allowed patients to face their most intense traumatic memories. Data on the highest reported subjective units of distress support this notion. Definite conclusions cannot be drawn from this study, but the use of the pressure vest to facilitate EMDR treatment warrants further research.