which causes heightened senses and emotional numbing. Psychosocial There is growing evidence linking physical and sexual abuse in childhood with the development of dissociative disorders. Childhood interpersonal trauma – emotional abuse in particular – is a significant predictor of a diagnosis of DPDR. Compared to other types of childhood trauma, emotional abuse has been found to be the most significant predictor both of a diagnosis of depersonalization disorder and of depersonalization scores, but not of general dissociation scores. Some studies suggest that greater emotional abuse and lower physical abuse predict depersonalization in adult women with post-traumatic stress disorder (PTSD). Patients with high interpersonal abuse histories (HIA) show significantly higher scores on the Cambridge Depersonalization Scale, when compared to a control group. Earlier age of abuse, increased duration and parental abuse tend to correlate with severity of dissociative symptoms. Besides traumatic experiences, other common precipitators of the disorder include severe stress, major depressive disorder, panic attacks, and psychoactive substances. People who live in highly individualistic cultures may be more vulnerable to depersonalization, due to threat hypersensitivity and an external locus of control. Neurobiology There is converging evidence that the prefrontal cortex may inhibit neural circuits that normally form the basis of emotional experience. In an fMRI study of DPDR patients, emotionally aversive scenes activated the right ventral prefrontal cortex. Participants demonstrated a reduced neural response in emotion-sensitive regions, as well as an increased response in regions associated with emotional regulation. In a similar test of emotional memory, depersonalization disorder patients did not process emotionally salient material in the same way as did healthy controls. In a test of skin conductance responses to unpleasant stimuli, the subjects showed a selective inhibitory mechanism on emotional processing. Studies are beginning to show that the temporoparietal junction has a role in multisensory integration, embodiment, and self-other distinction. Several studies analyzing brain MRI findings from DPDR patients found decreased cortical thickness in the right middle temporal gyrus, reduction in grey matter volume in the right caudate, thalamus, and occipital gyri, as well as lower white matter integrity in the left temporal and right temporoparietal regions. However, no structural changes in the amygdala were observed. A PET scan found functional abnormalities in the visual, auditory, and somatosensory cortex, as well as in areas responsible for an integrated body schema. One study examining EEG readings found frontal alpha wave overactivation and increased theta activity waves in the temporal