What characterizes 'delusions' in a psychological context?

Delusions are characterized by false beliefs that are firmly held despite clear evidence that contradicts them. In psychological terms, these beliefs are not influenced by reality or logical reasoning and persist even when a person is confronted with factual information that disproves their claims. For instance, an individual might believe they are being persecuted by an alien force or that they possess extraordinary abilities, regardless of external evidence to the contrary. This strong adherence to incorrect beliefs is a central feature of various mental health disorders, particularly psychotic disorders such as schizophrenia. Delusions can significantly impair an individual's functioning and affect their interactions with the world, making understanding and identifying them crucial in clinical settings.