GC: n

S: NIMH – (last access: 21 November 2014); DORLAND p. 484.

N: 1. “act of misleading someone,” early 15c.; as a form of mental derangement, 1550s, from Latin delusionem (nominative delusio) “a deceiving,” noun of action from past participle stem of deludere
2. The Online Etymology Dictionary makes a distinction between the terms delusion and illusion: Technically, delusion is a belief that, though false, has been surrendered to and accepted by the whole mind as a truth; illusion is an impression that, though false, is entertained provisionally on the recommendation of the senses or the imagination, but awaits full acceptance and may not influence action.
3. The word delusion is defined in Dorland’s Illustrated Medical Dictionary as: a false belief that is firmly maintained in spite of incontrovertible and obvious proof or evidence to the contrary and in spite of the fact that other members of the culture do not share the belief. Apart from other descriptions of types of delusion, the general medical and psychiatric term for delusion is delusion of control which is described as follows: the delusion that one’s thoughts, feelings, and actions are not one’s own but are being imposed by someone else or by some external force.
4. Delusion vs Delirium: Confusional States in the Medically Ill Patient:
Delirium results from an imbalance in certain neurotransmitters and is common in both ICU and non-ICU patients. It is also frequently missed or assigned a psychiatric etiology. This course presents the pathophysiology and implications of delirium along with an evidence based tool for rapid screening of the medically ill patient with delusions, delirium, or altered mental status.
5. Collocations:

  • Adj.: dangerous | foolish | paranoid.
  • Verb + delusion get, have, suffer (from).
  • Prep.: under a/the ~ He seemed to be under the delusion that he would make his fortune within a few years. | ~ about He had no delusions about his feelings for Kate. | ~ of She had delusions of persecution.
  • Phrases: delusions of grandeur (= a belief that you are more important than you actually are).

6. Cultural Interrelation: Joseph Heller’s Catch 22 (1961) is an american war-novel which depicts through black humour and absurd situations a bomber squadron in the last months of 2nd World War. When the heroe Yossarian is on air in his aircraft, he suffers from paranoid delusions: he affirms that thousands of people expressly want to kill him although it is a logical situation in war.

S: 1 & 2. OED – (last access: 21 November 2014). 3. DORLAND p. 484. 4. RCRMC – (last access: 21 November 2014). 5. OD – (last access: 23 May 2015). 6. GR – (last access: 8 December 2014); PBG.


CR: Capgras syndrome, Cotard’s syndrome, withdrawal syndrome, dementia.