Hello. Capgras Syndrome is also known as Capgras Delusion or Imposter Syndrome.
This is a rare condition where an individual believes that somebody close to them,
who could be their spouse, a family member, a close friend or even a pet,
has been replaced by a double or impostor.
Sometimes people believe that there are more than two versions of a person.
They believe that the person who is the imposter behaves just like the person whom the impostor has replaced,
and also that they assume the role of the person that they have replaced.
The belief is of delusional intensity - that is, nothing can be said to dissuade the person from the view.
Capgras Syndrome is not mentioned in either ICD-10 or DSM-5 classificatory systems.
The Capgras delusion can be very distressing for the person experiencing it,
and also the person who's being accused of being an impostor.
I'm Dr Beth Colby, a psychiatrist in London.
Joseph Capgras was a French psychiatrist. He co-authored a paper in 1923 in which the syndrome was first described.
The authors called it 'L'illusion des sosies,' which literally means 'illusion of look-alikes.'
The patient was a French woman known as Madame M,
who believed that her husband and also other people had been replaced by doubles.
Capgras syndrome was initially assumed to be a purely psychiatric disorder and symptomatic of schizophrenia.
However, today it's also understood as a neurological condition
in which the delusion results from organic brain lesions or degeneration.
The Capgras delusion is one of the class of delusional beliefs termed the delusional misidentification syndromes.
These involve the misidentification of people, places and objects.
Delusional misidentification syndromes are selective and specific, so that only a few people, places or objects are misidentified,
and that the misidentification always regards the same person, place or object.
Patients with Capgras syndrome recognize faces and other visual stimuli.
It's the central nervous system that scans the features of a face.
However, when seeing a familiar face,
patients with Capgras syndrome do not experience the emotional reaction to seeing the person
and therefore think that the person must have been replaced.
The emotional response normally observed would be autonomic skin conductance responses,
and this is low in seeing people who are strangers, and also low in Capgras syndrome.
Doctors still don't know exactly how Capgras develops,
but think a broken connection between the 2 systems prevents normal face, place or object recognition.
However there are several theories on what causes Capgras syndrome.
Some researchers believe that the cause is a problem with the brain, such as atrophy, lesions or cerebral dysfunction
Some believe that it's a combination of physical and cognitive changes in which feelings of disconnectedness contribute to the problem,
whilst others believe that it's a problem with processing information or an error in perception
which coincide with damaged or missing memories.
Patients with Capgras syndrome may exhibit violence and be dangerous.
Risk factors for this are past history of aggressive behaviour,
delusion against a specific person, and suspiciousness and hostility towards the person.
There's no standard treatment for Capgras syndrome.
the aim is to treat the cause
such as giving anti-dementia drugs to patients with dementia,
antipsychotics and therapy to patients with schizophrenia
and surgery if at all possible for patients with brain lesions.
I hope this has been interesting and informative.
Thank you for listening. 'Bye for now