When a person has or maintains a false belief or judgment about overt and objective external reality, and holds such views in defiance despite unquestionable authentication to the contrary, clinicians and therapists appropriately describe this as delusion and reflective of some form of mental disorder. Delusions are beliefs that are plainly untrue and that indicate an abnormality in the affected person’s content of thought. More problematic is these individuals are positively assured that the delusion is real.