Definition

1. Noun:
   • A psychiatric condition characterized by the presence of one or more delusions: Delusional disorder is a mental illness in which a person holds false beliefs (delusions) that persist for at least one month, without the prominent hallucinations, mood disturbances, or significant impairment in functioning typical of other psychotic disorders like schizophrenia.

Usage

• Noun:
  • The patient was diagnosed with a delusional disorder after persistently believing she was being followed by a government agency, despite a lack of evidence.
  • Treatment for delusional disorder often involves antipsychotic medication and psychotherapy.

Advanced Usage

• "Persecutory delusional disorder": A subtype where the central delusion involves the belief that one is being conspired against, cheated, spied on, followed, poisoned, harassed, or obstructed in the pursuit of long-term goals.
  • His persecutory delusional disorder made him distrustful of all his neighbors.
• "Erotomanic delusional disorder": A subtype characterized by the delusional belief that another person, often of higher status, is in love with the individual.
  • The celebrity obtained a restraining order against the fan suffering from erotomanic delusional disorder.

Variants and Related Words

• Delusion (n): A false belief held with strong conviction despite superior evidence to the contrary.
  • His delusion of grandeur led him to believe he was a secret king.
• Delusional (adj): Characterized by or holding false beliefs.
  • Her delusional thinking made it difficult for her to accept reality.

Synonyms

• Paranoia (in non-clinical, general use): An irrational and persistent feeling of being persecuted. (Note: In psychiatry, paranoia is a symptom, not a specific disorder diagnosis like delusional disorder).
• Monomania (archaic): Exaggerated or obsessive enthusiasm for or preoccupation with one thing. This term is largely historical and not a modern clinical diagnosis.

Related Phrases

• "Suffer from delusions": To experience false beliefs as part of a mental condition.
  • The individual suffering from delusions required professional intervention.
• "Systematized delusion": A single false belief or a network of related false beliefs that are logically interconnected and organized around a central theme, often seen in delusional disorder.
  • The psychiatrist noted the patient's complex, systematized delusion about a worldwide conspiracy.

Related Idioms

• "Living in a fantasy world": Behaving as if one's unrealistic beliefs or hopes are true. This idiom describes a state similar to having delusions but is not a clinical term.
  • With his unrealistic business plans, he's living in a fantasy world.

Noun

1. any mental disorder in which delusions play a significant role