Fregoli syndrome.

Fregoli syndrome is the delusional belief that one or more familiar persons, usually persecutors following the patient, repeatedly change their appearance. This syndrome has often been discussed as a variant of the Capgras syndrome in the literature, but these two syndromes have different phenomenological structures and age and sex distributions. The author presents a review of 34 cases of Fregoli syndrome in the English and French language literature, discussing the syndrome's definition, aetiology and course. It is suggested that although an organic substrate may be found in some cases, it is the dominant psychotic theme which determines the content of the syndrome.