Fregoli Delusion

The Fregoli delusion is a rare delusional misidentification syndrome in which a person becomes convinced that several different people they encounter are in fact one single person who is changing appearance or wearing a disguise each time, often accompanied by the further belief that this person is following or persecuting them. The condition is named after the Italian actor Leopoldo Fregoli, well known for his rapid on-stage costume changes, and the psychiatrists P. Courbon and G. Fail first documented it in 1927, describing a woman who believed that two actors from a theater were persistently pursuing her while disguised as other people she encountered. The delusion is understood to arise from faulty familiarity processing within the brain's face-recognition system, with brain lesions affecting the fusiform gyrus, temporal lobe, and right frontal regions disrupting the normal retrieval of visual memory and identity information; patients with the condition often also show broader visual memory deficits, hallucinations, and impaired executive function, alongside abnormalities in certain measurable patterns of brain electrical activity linked to working memory. The Fregoli delusion belongs to the same broader family of misidentification syndromes as the Capgras delusion, but the two run in conceptually opposite directions: where a person with Capgras delusion believes a familiar individual has been replaced by an unfamiliar impostor, a person with Fregoli delusion instead believes that unfamiliar individuals are secretly a single familiar person in disguise, and in rare cases a single patient has been documented experiencing both delusions at once.