The Cotard delusion or Cotard’s syndrome, also known as nihilistic or negation delusion, is a rare neuropsychiatric disorderdelusional belief that he or she is dead, does not exist, is putrefying or has lost his/her blood or internal organs. Rarely, it can include delusions of immortality.

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Young and Leafhead (1996, p155) describe a modern-day case of Cotard delusion in a patient who suffered brain injury after a motorcycle accident:

[The patient’s] symptoms occurred in the context of more general feelings of unreality and being dead. In January, 1990, after his discharge from hospital in Edinburgh, his mother took him to South Africa. He was convinced that he had been taken to hell (which was confirmed by the heat), and that he had died of septicaemia (which had been a risk early in his recovery), or perhaps from AIDS (he had read a story in The Scotsman about someone with AIDS who died from septicaemia), or from an overdose of a yellow fever injection. He thought he had ”borrowed my mother’s spirit to show me round hell”, and that he was asleep in Scotland.

http://en.wikipedia.org/wiki/Cotard_delusion