Depersonalization disorder (DPD) is a mental disorder in which the sufferer has persistent or recurrent feelings of depersonalization and/or derealization.In the DSM-5 it was combined with Derealization Disorder and renamed to Depersonalization/Derealization Disorder (DDPD).In the DSM-5 it remains classified as a dissociative disorder, while in the ICD-10 it is called depersonalization-derealization syndrome and classified as a neurotic disorder.ymptoms can be classified as either depersonalization or derealization. Depersonalization is described as feeling disconnected or estranged from one's body, thoughts, or emotions. Individuals experiencing depersonalization may report feeling as if they are in a dream or are watching themselves in a movie.