Emotional processing and outcome of imaginal flooding therapy in Vietnam veterans with chronic posttraumatic stress disorder.

This study examined emotional processing and outcome in 20 Vietnam veterans with chronic posttraumatic stress disorder (PTSD) who underwent imaginal flooding therapy. Results supported the occurrence of emotional processing, as manifest in significant activation, within-session habituation, and partial across-session habituation of physiologic and self-reported process variables. The flooding therapy produced only modest overall improvement, which was statistically significant for avoidance symptomatology measured by the impact of Events Scale (IOES) and number of intrusions per day recorded by the subject in a log. Symptomatic improvement appeared to generalize from a treated to an untreated experience. Heart rate activation during the first flooding session predicted a decrease in daily number of intrusive combat memories across the therapy. Otherwise, there was little association between extent of emotional processing and therapeutic outcome. The results provide limited support for the notion that mobilization of psychophysiologic arousal during exposure therapy predicts improvement.