Delusional disorder

, previously called paranoid disorder, is a type of serious mental illness — called a “psychosis”— in which a person cannot tell what is real from what is imagined. The main feature of this disorder is the presence of delusions, which are unshakable beliefs in something untrue.

What is considered delusional thinking?

Delusional reasoning can be described by an over-reliance on instinctive (rapid and non-reflective) thinking and an under-reliance on analytical thinking (deliberative, effortful). People with delusions are prone to making snap judgments and may form decisions quickly on the basis of little evidence.

What is the most common type of delusion?

Persecutory delusion

This is the most common form of delusional disorder. In this form, the affected person fears they are being stalked, spied upon, obstructed, poisoned, conspired against or harassed by other individuals or an organization.