Southern Illinois University medical students Sameer Vohra and Teschlyn Woods were discussing Dementia with Lewy Bodies today and mentioned that Capgras syndrome can sometimes be a manifestation of this particular type of dementia. I had never heard of Capgras syndrome, but they explained it to me. Here’s what Wikipedia has to say about it:
"The Capgras delusion (or Capgras's syndrome) 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in which a person holds a delusional belief that an acquaintance, usually a spouse or other close family member, has been replaced by an identical looking imposter.... It can occur in acute, transient, or chronic forms.
The delusion is most common in patients diagnosed with schizophrenia, although it can occur in a number of conditions including after brain injury and dementia. Although the Capgras delusion is commonly called a syndrome, because it can occur as part of, or alongside, various other disorders and conditions, some researchers have argued that it should be considered as a symptom, rather than a syndrome or classification in its own right."
It is named after Joseph Capgras (1873-1950), a French psychiatrist who first described the disorder in a 1923 paper by Capgras and Reboul-Lachaux. Here’s the link to the Wikipedia site describing the Capgras delusion: