Changes in salivary biomarkers with EMDR - Evidence for EMDR effectiveness in treatment of PTSD

The evidence for EMDR (Eye Movement Desensitization and Reprocessing) ’s effectiveness in treatment usually employs subjective rather than objective measures. Salivary stress biomarkers are considered a useful objective measure of stress. In this study, three salivary biomarkers were examined during EMDR treatment: cortisol (Crti.) as a measure of hypothalamic–pituitary–adrenal (HPA) axis response; secretory immunoglobulin A (s-IgA) as an immune function measure; and chromogranin A (CgA) as a measure of the sympathoadrenal system. Subjects were four adult PTSD (Post-traumatic stress disorder) clients (28–37 years old) who were treated with standard EMDR therapy. Changes in biomarker data during the course of EMDR treatment provided objective evidence for the effectiveness of EMDR therapy. First, Crti. and CgA levels decreased gradually during treatment, indicating that psychological stress was reduced by EMDR therapy. The change in s-IgA was predictably small, showing that the immune system recovered slowly from PTSD. Second, changes in CgA during EMDR sessions reflected the PTSD type (e.g., hyperarousal type or avoidance type) as defined by IES-R subscores. In clients with hyperarousal-type PTSD, pre-EMDR CgA levels were higher than post-treatment levels. Conversely, in avoidance-type clients, levels were lower before than after treatment. These changes were considered to reflect clients’ responses to the requirement that they recall their traumatic memories. The current study successfully shows that changes salivary biomarkers provide physiological evidence of therapeutic mechanism of EMDR in different types of PTSD.