The Capgras delusion is a rare disorder in which a person holds a delusional belief that an acquaintance, usually a spouse or other close family member, has been replaced by an identical looking impostor.

The Fregoli delusion is a rare disorder in which a person holds a delusional belief that different people are in fact a single person who changes appearance or is in disguise.

The syndrome of subjective doubles is a rare delusional misidentification syndrome in which a person suffers from the delusion that he or she has a double or doppelgänger with the same appearance, but usually with different character traits and leading a life of its own.

The Cotard delusion is a rare neuropsychiatric disorder in which a person holds a delusional belief that he or she is dead, does not exist, is putrefying or has lost his/her blood or internal organs.

Mirrored self-misidentification is the delusional belief that one's reflection in a mirror is some other person (often believed to be someone who is following them around).

Reduplicative paramnesia is the delusional belief that a place or location has been duplicated, existing in two or more places simultaneously, or that it has been 'relocated' to another site.