Some Patients With Cotard's Syndrome Believe They Are Dead. Others Believe They Are Immortal.

Cotard's syndrome is a rare psychiatric delusion in which a person becomes unshakably convinced of something that is biologically impossible about their own body. The most famous version, the one the syndrome is colloquially named for, is the conviction that the patient is dead — that the heart has stopped beating, the blood has stopped circulating, the organs are rotting from the inside. Patients have refused food on the grounds that corpses don't need to eat, asked relatives to bury them, and wept that no one will admit they have ceased to exist. The French neurologist Jules Cotard published the first description of the cluster in 1880, calling it le délire de négation, the delusion of negation.

The lesser-known half of the syndrome runs the opposite direction. A statistical review of historical cases found that only about 45 percent of patients experience the negative delusion — the conviction of nonexistence. The other 55 percent present with the positive form: the patient is convinced they are immortal, that they cannot be killed, that they have already become a kind of god. The two forms appear to be variations on the same underlying disturbance.

The neurological substrate, where it has been imaged, looks like a disconnection between the brain's face- and body-recognition systems and the limbic regions that attach feelings of familiarity and aliveness to perceptions. Cotard's first published patient, identified only as Mademoiselle X, refused all food on the grounds she had already died and was condemned to eternal damnation; she starved to death. A 2015 case report described a patient whose Cotard-like symptoms came from accumulated metabolites of an antiviral drug; the delusions resolved within hours of dialysis. Modern treatment more often involves antipsychotics and ECT.