Well actually two words, but this is just so bizarre I had to add it.
People with Cotard's syndrome (also called walking corpse syndrome or Cotard's delusion) believe that parts of their body are missing, or that they are dying, dead, or don’t exist. They may think nothing exists.
Cotard's syndrome is rare, with about 200 known cases worldwide.
Though the symptoms are extreme, most people get better with treatment.
People with this syndrome often become much less social. Sometimes, they may stop speaking at all. Some hear voices that tell them they're dead or dying.
Others may refuse to eat (because, among other reasons, they see no point since they're "dead"). Some may try to harm themselves.
In one well-documented case of Cotard's syndrome reported in 2008, a 53-year-old woman was admitted to the hospital after their family called 911. They said the woman believed that they were dead and smelled like rotting fish. They also asked to be taken to a morgue because they wanted to be with dead people.
Some experts think Cotard's syndrome results from two types of brain damage. The first changes the way people view themselves. The second makes them continue to believe this false view, even when they’re shown it’s not true. Not everyone agrees with this idea, though.