What is a delusion?

A delusion is defined as a firmly held false belief that persists despite clear evidence to the contrary. Individuals experiencing delusions have convictions that are inconsistent with reality, and these beliefs are typically resistant to reason or factual disproval. For instance, a person might believe they are being persecuted or that they possess extraordinary abilities, even when confronted with evidence that contradicts these beliefs. This characteristic of delusions distinguishes them from ordinary mistakes or misperceptions; delusions are robust and can significantly impair functioning and perception of reality.