Depersonalization is a subjective sense of unreality regarding various aspects of the self, experienced as disconnectedness from one's own body, mentations, feelings, or actions. When episodes of depersonalization are recurrent or persistent and lead to distress or dysfunction, the diagnosis of depersonalization disorder is made. Certain similarities in phenomenology, comorbidity, neurochemistry, and treatment response suggest a relationship to the obsessive-compulsive spectrum. However, depersonalization is a very poorly studied condition, and any conclusions must be viewed tentatively. Self-injurious behaviors are defined as intentionally self-inflicted bodily injuries without lethal intent. Basic categories are briefly described. Subsequently, the phenomenology and biology of both impulsive and compulsive self-injurious behaviors, and their relationship to the obsessive-compulsive spectrum, are discussed.