Cotard’s Syndrome – The patient believes he is dead.
Capgras Syndrome – The patient believes that a friend, spouse, parent, or other close family member has been replaced by an identical-looking impostor.
The second one reminds me of the old Steven Wright joke: “Last night somebody broke into my apartment and replaced everything with exact duplicates … When I pointed it out to my roommate, he said, ‘Do I know you?'”
