In an fMRI study of DPD 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 region of the left hemisphere. It is unclear whether genetics plays a role; however, there are many neurochemical and hormonal changes in individuals with depersonalization disorder. DPDR may be associated with dysregulation of the hypothalamic-pituitary-adrenal axis, the area of the brain involved in the "fight-or-flight" response. Patients demonstrate abnormal cortisol levels and basal activity.
Freudian theory is the basis for the description of depersonalization as a dissociative reaction, placed within the category of psychoneurotic disorders, in the first two editions of the Diagnostic and Statistical Manual of Mental Disorders.Some argue that because depersonalization and derealization are both impairments to ones ability to perceive reality, they are merely two facets of the same disorder. Depersonalization also differs from delusion in the sense that the patient is able to differentiate between reality and the symptoms they may experience. The ability to sense that something is unreal is maintained when experiencing symptoms of the disorder. The problem with properly defining depersonalization also lies within the understanding of what reality actually is. In order to comprehend the nature of reality we must incorporate all the subjective experiences throughout and thus the problem of obtaining an objective definition is brought about again. Society and culture
Depersonalization disorder has appeared in a variety of media. The director of the autobiographical documentary Tarnation, Jonathan Caouette, had depersonalization disorder. The screenwriter for the 2007 film Numb had depersonalization disorder, as does the films protagonist played by Matthew Perry. Norwegian painter Edvard Munchs famous masterpiece The Scream may have been inspired by depersonalization disorder. In Glen Hirshbergs novel The Snowmans Children, main female plot characters throughout the book had a condition that is revealed to be depersonalization disorder.