<PROPERTIES OF DELUSIONS (LIST) >
|LIST OF POSSIBLE DEFINING PROPERTIES OF DELUSIONS|
...as suggested by the literature. There is no logical limit to types of delusion-defining properties, be they descriptive of a delusion (e.g. implausible), etiological (e.g. predicated on false experiences of "significance"), descriptive of the relationship to the delusion (e.g. preoccupational), epistemological (e.g. unfalsifiable), etc., nor are these categories mutually exclusive (e.g. etiological may be epistemological). Properties may be necessary but not sufficient to define delusions (e.g.a belief). Some properties overlap (e.g. conviction and fixity). [References are provided for less commonly described properties or for direct quotes.] LIST OF PROPERTIES
1. A BELIEF (variously defined; for example: something "accepted as true...even though absolute certainty may be absent" - Neufeldt & Guralnik, 1988). Alternately, a "KNOWLEDGE CLAIM": delusions are subjectively experienced as known rather than believed (Spitzer, 1990, cf. McKenna 1991).
2. FALSE / IMPOSSIBLE / IMPLAUSIBLE / DISBELIEVED BY MOST OTHERS. [However, for Jaspers (1963), an accidentally true belief (e.g. that one's spouse is unfaithful) can still be a delusion if it arose through a psychotic process rather than a normal empirical process, so that one is right for the wrong reasons (p.106)].
3. HELD WITH "EXTRAORDINARY CONVICTION" (Jaspers, 1963)/ experienced with the certainty of an observed event (Jones & Watson, 1997).
4. FIXED / UNSHAKEABLE / UNFALSIFIABLE / FIRMLY SUSTAINED / IMPERVIOUS TO COUNTER-ARGUMENT OR COUNTER-EVIDENCE (criteria (3) & (4) "overlap": Garety, 1985) and see (5).
5. There is an UNJUSTIFIED CLAIM FOR INTERSUBJECTIVE VALIDITY (Spitzer, 1990, p. 392): "Delusions are statements about external reality which are uttered like statements about a mental state, i.e. with subjective certainty and incorrigible by others" (Spitzer, 1990, p. 391). That is, it's one thing to be sure of what you are feeling or experiencing ("I feel that it is not me who is thinking"), but another to claim intersubjective truth, without justification or correctability, for beliefs about events in the external world ("the CIA is sending thoughts into my head"). [A corollary might be: delusions are associated with implicit loss of awareness not only that one's belief about external reality requires evidence, but that other people expect the belief to be justified with evidence - Ed.]
6. Associated with LOSS OF PERSPECTIVE ABOUT HOW OTHERS VIEW THE BELIEF / SUBJECT EXPECTS OTHERS TO ACCEPT IT AS TRUE (Harrow & Miller, 1980); Eisen, Phillips, Baer, Beer, Atala & Rasmussen, 1998; Oulis, Mavreas, Mamounas & Stefanis, 1996).
7. "The person DOES NOT REPORT SUBJECTIVE EFFORTS TO RESIST THE BELIEF (Oltmanns, 1988), that is, to ignore, suppress, or neutralize the belief (through behavior), in contrast with obsessions, such as repeated thoughts of becoming contaminated in low risk situations, or of having inadvertently hurt someone in a car accident (DSM-IV, p. 418).
8. UNSHARED BY OTHERS, NOT ACCEPTED OR DETERMINED BY ONE'S CULTURE OR SUBCULTURE
9. ABOUT THE SELF (personally referent, rather than religious, scientific or political). Alternately: "content is crucially related to individual's personal fears, needs or security" (Reed 1988, p. 144)/"the subject has an emotional attachment to the belief" (Leeser & O'Donohue, 1999, p. 693).
10. ONCE REMOVED FROM IMMEDIATE EXPERIENCE (Cutting, 1997, p.124, who offers this example: not "I am now experiencing my arm as telescoping" but "I have ball bearings inside my body")
11. INTERFERING WITH FUNCTIONING / INFLUENCING BEHAVIOR
12. EVOKING STRONG FEELINGS (distressing or elating)
13. PRE-OCCUPYING / FREQUENTLY THOUGHT OR TALKED ABOUT
14. Associated with a SENSE OF URGENCY (e.g. Schneider, 1959, p. 104).
15. ARISING FROM AN INFERENTIAL ERROR (generally understood as some kind of rational or logical error, an error of conscious thought).
16. ARISING FROM AN INTUITIVE ERROR (Krakauer 2000; Sigmund,1998). EXPERIENCED AS KNOWLEDGE BY DIRECT REVELATION (Podvoll, 1990, p.161); UNMEDIATED BY THOUGHT, experienced as immediate knowledge, not based on interpretation (Jaspers, 1963, 101-102); see criterion (15).
17. ARISING AS A "DELUSIONAL PERCEPTION" in which an abnormal meaning, generally self-referential, is attached to a genuine perception, for no understandable cause, not as an interpretation but as immediate knowledge, and often experienced as coming from a 'higher reality' (see Jaspers, 1963, pp.101-102 and Schneider, 1974, p.33 ff and 1959, p. 104 ff).
Similarly: "The belief is typically supported by (or originates from) trivial occurrences that are interpreted by the subject as highly unusual, significant, and/or having personal reference." (Leeser & O'Donohue, 1999, p. 693). (This experience differs from normal symbolic perception, in which a coincidence might be taken as an omen (see Maher & Spitzer, 1993.)
And: There is a "high subjective certainty in the sense of an elimination of the possibility of chance coincidences..." (Berner, 1975).
18. HAVING OR NOT HAVING SPECIFIC THEMATIC CONTENTS (e. g."I'm Jesus Christ" vs. the unrealistic belief that one is overweight (in anorexia) or hideously ugly (in Body Dysmorphic Disorder). Similarly, there may be some monosymptomatic or content-specific delusions (e. g. Cotard's syndrome: belief that oneself is dead) that are generally associated with lesions of specific neurological areas (Malloy & Richardson, 1994), so that content may suggest etiological distinctions among beliefs.
19. Implying a "LOSS OF THE BENEFIT OF...ACCUMULATED LIFE EXPERIENCE AS TO COMMON CAUSAL RELATIONSHIPS AND THE RANGE OF PHYSICAL POSSIBILITIES" (Chapman & Chapman, 1988, p. 179).