Cotard Syndrome, sometimes referred to as Walking Corpse Syndrome, is a serious delusion associated with schizophrenia and other mental illnesses, as well as can be brought on by brain injury. Cotard Syndrome can also manifest in drug addicted people, more predominately associated with addicts who abuse cocaine, methamphetamine, or speed. Cotard Syndrome involves a strong delusion that one is dead (either physically dead or metaphorically dead), has no soul, is missing various internal organs, is rotting or decaying, is infested with maggots or worms, or simply does not exist. Many sufferers report attempting to kill or harm themselves to prove they are dead. A very small minority of sufferers may hold to further delusions of a demonic spirit or entity which has taken over their 'corpse' and which forces them to commit acts of violence or harm to other people. Even rarer are cases in which sufferers possess the added delusion of being immortal. Certain people diagnosed with this condition, and cases where the delusions are connected to deep depression, have responded well to electroconvulsive therapy. If the condition arises from drug abuse, the delusion may disappear when the individual comes down off their high or seeks treatment for their addiction. For cases which involve brain injury, there is little to be done at this time, other than behavioral therapy.
The video below was made by a person diagnosed with Cotard Syndrom.
Health Talk: Walking Corpse Syndrome
Cotard's syndrome and delayed diagnosis in Kashmir, India
Cotard's Syndrome in a Homeless Man