The Cotard delusion or Cotard's syndrome or Walking Corpse Syndrome is a rare neuropsychiatric disorder in which people hold a delusional belief that they are dead (either figuratively or literally), do not exist, are putrefying, or have lost their blood or internal organs. In rare instances, it may include delusions of immortality. The syndrome is named after Jules Cotard (1840–1889), a French neurologist who first described the condition.