APA Dictionary of Psychology

a disorder characterized by the delusional misidentification of oneself, other people, places, or objects. The misidentification may be expressed as the mistaken belief that a person has altered their identity in some way, either physically or psychologically, or that some place or object has undergone transformation. Also called delusional misidentification syndrome. See also Capgras syndrome; Fregoli’s phenomenon; intermetamorphosis syndrome.