Reexperiencing/hyperaroused and dissociative states in posttraumatic stress disorder: no established therapy; combined drug, psychosocial interventions may help

A recent review and metaanalysis found that persons with PTSD tend to exhibit greater brain activation in the amygdala and insula than persons without PTSD; these structures are involved in fear conditioning and the perception of bodily states (among other functions), respectively. 19 Moreover, the dorsal anterior cingulate cortex (ACC), rostral ACC and ventromedial prefrontal cortex, which are involved in the experience and regulation of emotion, have repeatedly been observed to be less activated in patients with PTSD than in controls who have a history of trauma but not PTSD.19 Our research has shown that in patients with PTSD, psychobiological responses to recalling traumatic experiences can differ significantly, and a sizable proportion do not fit the conventionally studied "reexperiencing/ hyperaroused" response.20,21 For example, in our initial brain imaging studies, approximately 70% of patients relived their traumatic experience and showed an increase in heart rate while recalling the traumatic memory,11,13 while the other 30% had a dissociative response with no concomitant increase in heart rate.14,15 We have investigated the neuronal circuitry that underlies reexperiencing/ hyperaroused and dissociative responses in PTSD using BOLD fMRI and script-driven imagery. [...] these findings have important implications for treatment, including the need to assess patients with PTSD for dissociative symptomatology and to treat dissociative symptoms before using exposurebased approaches.