Definition:
Delusions refer to irrational perceptions or beliefs that an individual actively defends. Despite logical evidence to the contrary, an individual will hold onto the irrational beliefs with certainty.
According to the DSM-IV-TR, a delusion is:
A false belief based on incorrect inference about external reality that is firmly sustained despite what almost everybody else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary. The belief is not one ordinarily accepted by other members of the person's culture or subculture.
