What are nihilistic delusions?

Nihilistic delusions are persistent beliefs that a subject does not exist or is dead. Like other delusions, these beliefs endure even when patients are presented with information that contradicts them, such as a third party's acknowledgment that the patient is alive and appears to exist. This psychological phenomenon was first described in the 19th century by Jules Cotard, a French researcher, and is sometimes referred to as a Cotard illusion in reference to this. It can be seen in patients with certain mental health conditions, as well as in people with brain injuries.

Patients with nihilistic delusions may express them in a number of different ways. Some patients simply believe that they themselves do not exist and, in some cases, have never existed. They do not recognize the information that invalidates this claim and may think that they are invisible or inaudible to the people around them. Others think they are dead, and some experience vivid hallucinations to accompany the delusion, believing they are rotting corpses, for example, or thinking limbs are missing.

If a patient is asked by a health care provider, he or she is often unable to reveal personal information. Patients who think they don't exist believe they don't have names, ages, or parents, for example. They may not remember anything from their past. Those who believe they are dead can tell health care providers how they died and can offer information about their lives.

Cotard believed that nihilistic delusions were the result of "negativism". The actual psychology behind them may be somewhat more complex. Patients with conditions such as schizophrenia, bipolar disorder, and borderline personality disorder may develop a sense of disconnection from the world around them. This can manifest in the form of delusions that seem quite logical to the patient, even if they seem strange to onlookers. Thus, a patient may develop nihilistic delusions after being ignored or silenced in an attempt to explain those experiences.

In the case of brain injuries, delusions may result from damage to parts of the brain involved in self-perception. These patients are difficult to treat as they may not respond to therapy and medications in the same way as those with mental illness, because the problems with the brain are so different. After an injury, the brain can gradually reassign connections and build new associations, but this may take time. During this process, the patient may need supportive care to perform tasks of daily living and slowly erode nihilistic delusions.

Go up