Depersonalization / Derealization Disorder By David Spiegel, MD, Stanford University School of Medicine Reviewed / Revised May 2023 View Patient Education Etiology Symptoms and Signs Diagnosis Treatment Prognosis Depersonalization / derealization disorder is a type of dissociative disorder that consists of persistent or recurrent feelings of being detached (dissociated) from one's body or mental processes, usually with a feeling of being an outside observer of one's life (depersonalization) or of being detached from one's surroundings (derealization).