This study was designed to investigate the question of whether psychophysiological changes during EMDR sessions are related to subjective and objective reduction of PTSD symptoms. During-session changes in autonomic tone in relation to session-to-session changes of subjective stress, trauma-related symptoms, and psychophysiological reactions during a traumatic reminder were investigated in 10 patients suffering from single-trauma PTSD. Treatment duration followed each patient’s individual needs and ranged between 1 and 4 sessions, resulting in a total of 24 EMDR treatment sessions from which psychophysiological data were completely recorded. Treatment with EMDR was followed by a significant reduction of trauma-related symptoms, elimination of the PTSD diagnosis in 8 of the 10 participants, as well as by significantly reduced psychophysiological reactivity to an individualized trauma script. Psychophysiological dearousal in sessions correlated significantly with decrease in script-related reactions in heart rate and parasympathetic tone, and with changes in subjective disturbance. Our results indicate that information processing during EMDR is followed by during-session decrease in psychophysiological activity, reduced subjective disturbance and reduced stress reactivity to traumatic memory.

EMDR combines stimuli that evoke divided attention – e.g. eye movements – with exposure to traumatic memories. Our objective was to investigate psycho-physiological correlates of EMDR during treatment sessions. A total of 55 treatment sessions from 10 patients with PTSD was monitored applying impedance cardiography. Onset of every stimulation/exposure period (n=811) was marked and effects within and across stimulation sets on heart rate (HR), heart rate variability (HRV), pre-ejection period (PEP) and respiration rate were examined. At stimulation onsets a sharp increase of HRV and a significant decrease of HR was noticed indicating de-arousal. During ongoing stimulation, PEP and HRV decreased significantly while respiration rate significantly increased, indicating stress-related arousal. However, across entire sessions a significant decrease of psycho-physiological activity was noticed, evidenced by progressively decreasing HR and increasing HRV. These findings suggest that EMDR is associated with patterns of autonomic activity associated with substantial psycho-physiological de-arousal over time.