The Capgras delusion theory (or Capgras syndrome) is a disorder in which a person holds a delusion that a friend, spouse, parent, or other close family member has been replaced by an identical-looking impostor. The Capgras delusion is classified as a delusional misidentification syndrome, a class of delusional beliefs that involves the misidentification of people, places, or objects. It can occur in acute, transient, or chronic forms. The delusion is most common in patients diagnosed with schizophrenia, although it can occur in connection with a number of conditions, including brain injury and dementia. An interesting variant involves the misidentification of the person’s mirror image as a separate person.