Capgras Syndrome

Capgras Syndrome, also known as Capgras Delusion, is the delusion that others, or the self, have been replaced by imposters. It is classified under delusion of mis-identification or substitution and is also known as delusion of doubles.

The delusion was named in honour of Joseph Capgras who described the first case. It typically follows the development of negative feelings toward the other person that the subject cannot accept and therefore attributes to the imposter.

Capgras syndrome is assumed to be a rare phenomenon, initially reported to be associated only with psychiatric diseases, including paranoid schizophrenia and schizoaffective disorder. However, more recently Capgras syndrome has also been described in neurological conditions including epilepsy, in cerebrovascular disease, after head trauma, with pituitary tumor, and especially in neurodegenerative diseases such as Alzheimer disease and Lewy body disease.

Capgras syndrome is also known as l’illusion des sosies.