Cotard delusion, also known as walking corpse syndrome or Cotard's syndrome, is a rare mental disorder in which the affected person holds the delusional belief that they are already dead, do not exist, are putrefying, or have lost their blood or internal organs. Statistical analysis of a hundred-patient cohort indicated that the denial of self-existence is a symptom present in 45% of the cases of Cotard's syndrome; the other 55% of the patients presented delusions of immortality. symptoms occurred in the context of more general feelings of unreality and being dead. In January 1990, after his discharge from hospital in Edinburgh, his mother took him to South Africa. He was convinced that he had been taken to Hell (which was confirmed by the heat), and that he had died of sepsis (which had been a risk early in his recovery), or perhaps from AIDS (he had read a story in The Scotsman about someone with AIDS who died from sepsis), or from an overdose of a yellow fever injection. He thought he had 'borrowed mother's spirit to show around hell', and that she was asleep in Scotland. Cotard delusion, also known as walking corpse syndrome or Cotard's syndrome, is a rare mental disorder in which the affected person holds the delusional belief that they are already dead, do not exist, are putrefying, or have lost their blood or internal organs. Statistical analysis of a hundred-patient cohort indicated that the denial of self-existence is a symptom present in 45% of the cases of Cotard's syndrome; the other 55% of the patients presented 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 and of her need to eat. She said that she was condemned to eternal damnation and therefore could not die a natural death. In the course of suffering 'The Delirium of Negation', Mademoiselle X died of starvation. The Cotard delusion is not mentioned in either the Diagnostic and Statistical Manual of Mental Disorders (DSM) or the tenth edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) of the World Health Organization. The delusion of negation is the central symptom in Cotard's syndrome. The patient afflicted with this mental illness usually denies their own existence, the existence of a certain body part, or the existence of a portion of their body. Cotard's syndrome exists in three stages: (i) Germination stage—the symptoms of psychotic depression and of hypochondria appear; (ii) Blooming stage—the full development of the syndrome and the delusions of negation; and (iii) Chronic stage—continued, severe delusions along with chronic psychiatric depression. The Cotard syndrome withdraws the afflicted person from other people due to the neglect of their personal hygiene and physical health. The delusion of negation of self prevents the patient from making sense of external reality, which then produces a distorted view of the external world. Such a delusion of negation is usually found in the psychotic patient who also presents with schizophrenia. Although a diagnosis of Cotard's syndrome does not require the patient's having had hallucinations, the strong delusions of negation are comparable to those found in schizophrenic patients. The article Betwixt Life and Death: Case Studies of the Cotard Delusion (1996) describes a contemporary case of Cotard delusion, which occurred in a Scotsman whose brain was damaged in a motorcycle accident: The article Recurrent Postictal Depression with Cotard Delusion (2005) describes the case of a fourteen-year-old epileptic boy who experienced Cotard syndrome after seizures. His mental health history was of a boy expressing themes of death, chronic sadness, decreased physical activity in playtime, social withdrawal, and disturbed biological functions. About twice a year, the boy suffered 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. The underlying neurophysiology and psychopathology of Cotard syndrome might be related to problems of delusional misidentification. Neurologically, the Cotard delusion (negation of the Self) is thought to be related to the 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. If the observed face is that of a person known to the patient, they experience that face as the face of an impostor (the Capgras delusion). If the patient sees their own face, they might perceive no association between the face and their own sense of Self—which results in the patient believing that they do not exist (the Cotard delusion).