Cotard's syndrome

'''Cotard's syndrome**, also called **Cotard's delusion** or **walking corpse syndrome''', is a rare mental disorder. A person with this condition believes that they are dead, do not exist, or that parts of their body are missing or rotting. Some people believe they have no blood or no internal organs.

Studies of 100 patients showed that about 45% believed they did not exist at all. The other 55% believed they were immortal and could never die.

In 1880, the neurologist and psychiatrist Jules Cotard first described this illness. He called it , which means "the delusion of denial". Mild cases include sadness and strong self-hate. Severe cases include strong false beliefs and long-term depression.

One famous case is called "Mademoiselle X". She was a woman who believed parts of her body did not exist and thought she did not need to eat. She believed she was cursed to suffer forever and could not die naturally. Because of this belief, she stopped eating and later died from starvation.

Cotard's syndrome is not listed in the *Diagnostic and Statistical Manual of Mental Disorders* (DSM) or in the 10th edition of the *International Statistical Classification of Diseases and Related Health Problems* (ICD-10) by the World Health Organization.

## Signs and symptoms 
The main symptom of Cotard's syndrome is a strong false belief that the person does not exist or that parts of their body are missing or dead.

Doctors describe three stages of Cotard's syndrome:

# Early stage: the person may have severe depression and worry too much about their health.
# Middle stage: the false beliefs become strong and clear.
# Late stage: the false beliefs continue for a long time along with long-term depression.

People with Cotard's syndrome may stop taking care of themselves and stay away from other people. Because they believe they do not exist, they may not understand the real world correctly. These beliefs can be similar to those seen in schizophrenia, even though hallucinations are not always present.

### Distorted reality 
Some people with Cotard's syndrome believe they are dead or living in another world. One reported case involved a man who believed he was in Hell after a motorcycle accident. He thought he had already died and that the people around him were not real.

Another case described a 14-year-old boy with epilepsy who developed Cotard's syndrome after seizures. During episodes that lasted weeks or months, he believed that everyone and everything was dead, including himself. He showed no interest in activities or other people during these times.

## Pathophysiology 
Doctors are not fully sure what causes Cotard's syndrome, but it is linked to problems in how the brain sees faces and emotions.

Some researchers believe Cotard's syndrome is related to Capgras delusion. Both conditions may be caused by problems in the fusiform gyrus, which helps sees faces, and the amygdala, which links emotions to faces.

Because of these brain problems, a face may not feel familiar to the patient. This can cause derealization, where the world feels made-up. If the patient sees their own face and feels no connection to it, they may believe they do not exist. It can also occur in people with severe depression, brain tumors, and migraine headaches.

Medical studies show that Cotard's syndrome is linked to damage in the parietal lobe and reduced size of parts of the frontal lobe.

In rare cases, Cotard's syndrome has been caused by reactions to medicines. This happens when a drug by-product grows in the blood, especially in people with kidney problems. In these cases, hemodialysis has been shown to quickly improve symptoms.

When Cotard's syndrome is caused by a drug reaction, stopping the medicine is important. Hemodialysis can remove the harmful substance from the blood and help symptoms improve quickly.

## Case studies 
## Related pages 
* Prosopagnosia
* Zombie

## References 
*Young, A., Robertson, I., Hellawell, D., De Pauw, K., & Pentland, B. (1992). Cotard delusion after brain injury. Psychological Medicine, 22(3), 799–804.