Capgras delusion
psychiatric disorder (syndrome) in which a person holds a delusion that a family member has been replaced by an identical imposter
Capgras syndrome (pronunciation: Cap-gra sin-druhm) is when an individual holds a belief that a loved one is an impostor. This is in the category of Delusional Misidentification Syndromes. (or DMS)
The cause of Capgras syndrome is unclear but some risk factors are; having dementia, head trauma, psychotic disorders like schizophrenia, etc.
Capgras syndrome was first described by French psychiatrist Jean Marie joseph Capgrasin his paper which was written with his colleague, Jean Reboul-Lachaux. That is why it is called Capgras syndrome.