Delusional misidentification syndrome is an umbrella term for a group of delusional disorders that occur in the context of mental or neurological illness. They all involve a belief that the identity of a person, object or place has somehow changed or has been altered.
This syndrome is usually considered to include four main variants 1:
- The Capgras delusion - the belief that (usually) a close relative or spouse has been replaced by an identical-looking impostor.
- The Fregoli delusion - the belief that various people that the believer meets are actually the same person in disguise.
- Intermetamorphosis - the belief that people in the environment swap identities with each other whilst maintaining the same appearance.
- Subjective doubles - in which a person believes there is a doppelganger or double of him or herself carrying out independent actions.
- Reduplicative paramnesia - the belief that a familiar person, place, object or body part has been duplicated. For example, a person may believe that they are in fact not in the hospital to which they were admitted, but an identical looking hospital in a different part of the country, despite this being obviously false2.
- 'Delusional companions' - the belief that objects (such as soft toys) are sentient beings3.
- Clonal pluralization of the self - where a person believes there are multiple versions of him or herself in existence4.
See also
References
1Ellis, H.D., Luauté, J.P. & Retterstol, N. (1994) Delusional misidentification syndromes. Psychopathology, 27, 117-120.
2Benson DF, Gardner H, Meadows JC. (1976) Reduplicative paramnesia. Neurology, 26(2), 147-51.
3Shanks, M.F. & Venneri, A. (2002) The emergence of delusional companions in Alzheimer's disease: An unusual misidentification syndrome. Cognitive Neuropsychiatry, 7(4), 317-28.
4Voros V, Tenyi T, Simon M, Trixler M. (2003) 'Clonal pluralization of the self': a new form of delusional misidentification syndrome. Psychopathology, 36(1), 46-8.
5Sno, H.N. (1994) A continuum of misidentification symptoms. Psychopathology, 27(3-5), 144-7.