Cotards delusion, also known as walking corpse syndrome or Cotards syndrome, is a rare mental disorder in which the affected person holds the delusional belief that they are dead, do not exist, are putrefying, or have lost their blood or internal organs. Statistical analysis of a hundred-patient cohort indicated that denial of self-existence is present in 45% of the cases of Cotards syndrome; the other 55% of the patients presented with delusions of immortality.In 1880, the neurologist Jules Cotard described the condition as le délire des négations ("the delirium of negation"), a psychiatric syndrome of varied severity. A mild case is characterized by despair and self-loathing, while a severe case is characterized by intense delusions of negation, and chronic psychiatric depression.The case of "Mademoiselle X" describes a woman who denied the existence of parts of her body (somatoparaphrenia) and of her need to eat. She claimed that she was condemned to eternal damnation, and therefore could not die a natural death. In the course of experiencing "the delirium of negation", Mademoiselle X died of starvation.Cotards delusion is not mentioned in either the Diagnostic and Statistical Manual of Mental Disorders (DSM) or the 10th edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) of the World Health Organization. Signs and symptoms
Delusions of negation are the central symptom in Cotards syndrome. The patient usually denies their own existence, the existence of a certain body part, or the existence of a portion of their body.
He thought he had "borrowed [his] mothers spirit to show [him] around Hell" and that she was asleep in Scotland. The article Recurrent Postictal Depression with Cotard Delusion (2005) describes the case of a 14-year-old epileptic boy who experienced Cotards syndrome after seizures. His mental health history showed themes of death, chronic sadness, decreased physical activity in leisure time, social withdrawal, and disturbed biological functions. About twice a year, the boy had episodes that lasted between three weeks and three months. In the course of each episode, he said that everyone and everything was dead (including trees), described himself as a dead body, and warned that the world would be destroyed within hours. Throughout the episode, the boy showed no response to pleasurable stimuli, and had no interest in social activities. Pathophysiology
The underlying neurophysiology and psychopathology of Cotards syndrome might be related to problems of delusional misidentification. Neurologically, Cotards delusion (negation of the self) is thought to be related to Capgras delusion (people replaced by impostors); each type of delusion is thought to result from neural misfiring in the fusiform face area of the brain, which recognizes faces, and in the amygdalae, which associate emotions to a recognized face.The neural disconnection creates in the patient a sense that the face they are observing is not the face of the person to whom it belongs; therefore, that face lacks the familiarity (recognition) normally associated with it. This results in derealization or a disconnection from the environment.