Capgras syndrome, also known as Capgras delusion, is a rare psychological disorder in which the afflicted person believes that a friend, family member, or a loved one has been replaced by an identical impostor or a double. People suffering from this disorder are unable to recognize or acknowledge the familiar person's identity, even though there is no physical or any other evidence to support the belief. This condition is often associated with certain mental health disorders or brain injuries and can be treated through psychological therapy and medication.
