Capgras delusion
Table of Contents
The
Capgras delusion
or
Capgras' syndrome
is a rare disorder in which a person holds a
delusional
belief that an acquaintance, usually a close family member or
spouse
, has been replaced by an identical looking
imposter
. Capgras delusion is classed as a
delusional misidentification syndrome
, a class of delusional beliefs that involves the misidentification of people, places or objects. Additionally Capgras delusion is termed a
monothematic delusion
because it has been shown to occur on its own outside of any other delusions.
Although Capgras is commonly called a syndrome, it may occur as part of, or alongside various other disorders and conditions, such as
schizophrenia
and
neurological illness
. Therefore some researchers have argued that it should be considered as a symptom, rather than a syndrome or classification in its own right
.
Overview
It is named after
Joseph Capgras
(
1873
-
1950
), a
French
psychiatrist
who first described the disorder in a paper by Capgras and Reboul-Lachaux
in
1923
. They used the term
l'illusion des sosies
(the illusion of doubles) to describe the case of a French woman who complained that various "doubles" had taken the place of people she knew. However, the term
illusion
has a subtly different meaning from
delusion
in psychiatry so "Capgras delusion" is used as a more suitable name.
This case is taken from a
1991
report by Passer and Warnock
Mrs. D, a 74-year old married housewife, recently discharged from a local hospital after her first psychiatric admission, presented to our facility for a second opinion. At the time of her admission earlier in the year, she had received the diagnosis of atypical psychosis because of her belief that her husband had been replaced by another unrelated man. She refused to sleep with the imposter, locked her bedroom and door at night, asked her son for a gun, and finally fought with the police when attempts were made to hospitalise her. At times she believed her husband was her long deceased father. She easily recognised other family members and would misidentify her husband only.
Causes
There is strong
neuropsychological
evidence that the Capgras delusion is, at least in part, related to a loss of
emotional
response to familiar faces. This is in the context of generally good (although not always perfectly intact)
face perception
abilities. This seems to be the reverse of
prosopagnosia
, a condition where
conscious
face recognition abilities are lost, despite sufferers still showing a covert emotional response to familiar faces, detectable by measuring (for example) skin conductance.
These results and others gained from studying the Capgras delusion have helped uncover the normal
psychology
of face recognition
. The study of
mental illness
to uncover the normal function of the
mind
and
brain
is known as
cognitive neuropsychiatry
, and study of the Capgras delusion has been cited an early success in this field of study.
In fiction
Situations in which the protagonist (and the audience) knows that their acquaintances have been replaced by spies,
alien
s or
monster
s while the rest of the people think the protagonist insane appear in several works of
horror
and
science-fiction
. Well-known examples include
Invasion of the Body Snatchers
,
The Stepford Wives
,
Total Recall
and
The Faculty
.
References
Capgras, J. & Reboul-Lachaux, J. (1923). Illusion des sosies dans un delire systematise chronique.
Bulletin de la Societe Clinique de Medicine Mentale
2
6–16.
Ellis, H.D.; Whitley, J.; & Luaute, J.P. (1994).
Delusional misidentification. The three original papers on the Capgras, Frégoli and intermetamorphosis delusions (Classic Text No. 17).
History of Psychiatry
5
(17) 117–146.
Passer, K.M. & Warnock, J.K. (1991).
Pimozide in the treatment of Capgras' syndrome. A case report.
Psychosomatics
32
(4) 446–448.
Forstl, H.; Almeida, O.P.; Owen, A.M.; Burns, A.; & Howard, R. (1991).
Psychiatric, neurological and medical aspects of misidentification syndromes: a review of 260 cases.
Psychological Medicine
21
(4) 905–910.
Ellis, H.D. & Lewis, M.B. (2001).
Capgras delusion: a window on face recognition.
Trends in Cognitive Sciences
5
(4) 149–156.
Ramachandran, V.S. (1999).
Phantoms in the Brain: Probing the Mysteries of the Human Mind
. New York: Harper Collins Ltd. ISBN 0688172172
See also