In 1880 French neurologist Jules Cotard described the delusion of negation, now called Cotard syndrome or walking corpse syndrome, in which a person becomes convinced they are dead, rotting, bloodless, or missing organs. His case of Mademoiselle X denied parts of her body and any need to eat, believed she was eternally damned and therefore could not die a natural death, and died of starvation. This episode explains why, in one cohort of 100 patients, 45 percent denied their own existence while 55 percent held delusions of immortality, and walks through the germination, blooming, and chronic stages. It also covers why the condition is absent from the DSM and ICD-10, treated as a symptom of psychosis, depression, or brain tumors.

In a 1996 case a Scotsman, injured in a motorcycle crash, felt the heat of South Africa and concluded he was in hell, saying he had borrowed his mother’s spirit as a guide. A 14 year old with epilepsy declared even the trees dead after seizures. The episode links Cotard to Capgras delusion, where the fusiform face area recognizes a face but the emotional signal from the amygdala goes silent, and to lesions of the parietal lobe. In some patients with kidney failure, a metabolite of acyclovir called CMMG triggered the delusion, which cleared within hours of hemodialysis.

• The Scotsman’s shifting explanations for his death: sepsis, AIDS, and a yellow fever shot
• Greater brain atrophy in the median frontal lobe of patients compared with controls
• Electroconvulsive therapy as an effective treatment in depressed patients with Cotard
• Caden Cotard in Charlie Kaufman’s Synecdoche, New York, plus Hannibal, Luther, and Scrubs
• Esmé Weijun Wang’s essays and Per Ohlin of Mayhem, known as Dead, and his corpse paint