Editing Delusion (section)

==Diagnosis==
[[File:Airloom.gif|thumb|[[James Tilly Matthews]] illustrated this picture of a machine called an "air loom", which he believed was being used to torture him and others for political purposes.]]
The modern definition and Jaspers' original criteria have been criticised, as counter-examples can be shown for every defining feature.

Studies on [[Involuntary commitment|psychiatric patients]] show that delusions vary in intensity and conviction over time, which suggests that certainty and incorrigibility are not necessary components of a delusional belief.<ref>{{cite journal | vauthors = Myin-Germeys I, Nicolson NA, Delespaul PA | title = The context of delusional experiences in the daily life of patients with schizophrenia | journal = Psychological Medicine | volume = 31 | issue = 3 | pages = 489–498 | date = April 2001 | pmid = 11305857 | doi = 10.1017/s0033291701003646 | s2cid = 25884819 }}</ref>

Delusions do not necessarily have to be false or 'incorrect inferences about external reality'.<ref>{{cite journal | vauthors = Spitzer M | title = On defining delusions | journal = Comprehensive Psychiatry | volume = 31 | issue = 5 | pages = 377–397 | year = 1990 | pmid = 2225797 | doi = 10.1016/0010-440X(90)90023-L }}<br /></ref> Some religious or spiritual beliefs by their nature may not be falsifiable, and hence cannot be described as false or incorrect, no matter whether the person holding these beliefs was diagnosed as delusional or not.<ref>{{cite book | vauthors = Young AW |chapter=Wondrous strange: The neuropsychology of abnormal beliefs |editor1=Coltheart M. |editor2=Davis M. |title=Pathologies of belief |publisher=Blackwell |location=Oxford |year=2000 |isbn=0-631-22136-0 |pages=47–74 }}</ref>
In other situations the delusion may turn out to be true belief.<ref>{{cite journal | vauthors = Jones E |title=The phenomenology of abnormal belief |journal=Philosophy, Psychiatry, & Psychology |volume=6 |pages=1–16 |year=1999 |url=http://muse.jhu.edu/journals/philosophy_psychiatry_and_psychology/toc/ppp6.1.html}}</ref> For example, in [[delusional jealousy]], where a person believes that their partner is being unfaithful (and may even follow them into the bathroom believing them to be seeing their lover even during the briefest of partings), it may actually be true that the partner is having sexual relations with another person. In this case, the delusion does not cease to be a delusion because the content later turns out to be verified as true or the partner actually chose to engage in the behavior of which they were being accused.{{cn|date=April 2025}}

In other cases, the belief may be mistakenly assumed to be false by a doctor or psychiatrist assessing it, just because it ''seems'' to be unlikely, bizarre or held with excessive conviction. Psychiatrists rarely have the time or resources to check the validity of a person's claims leading to some true beliefs to be erroneously classified as delusional.<ref>{{cite book | vauthors = Maher BA |chapter=Anomalous experience and delusional thinking: The logic of explanations |editor1=Oltmanns T. |editor2=Maher B. |title=Delusional Beliefs |publisher=Wiley Interscience |location=New York |year=1988 |isbn=0-471-83635-4 }}</ref> This is known as the [[Martha Mitchell effect]], after the wife of the [[United States Attorney General|attorney general]] who alleged that illegal activity was taking place in the [[White House]]. At the time, her claims were thought to be signs of mental illness, and only after the [[Watergate scandal]] broke was she proved right (and hence sane).<ref>{{Cite book |last=Colman |first=Andrew M. |url=https://books.google.com/books?id=UDnvBQAAQBAJ&pg=PA441#v=onepage&q&f=false |title=A dictionary of psychology |date=2015 |publisher=[[Oxford University Press]] |isbn=978-0-19-965768-1 |edition=4th |series=Oxford quick reference |location=Oxford |pages=441}}</ref>

Similar factors have led to criticisms of Jaspers' definition of true delusions as being ultimately 'un-understandable'. Critics (such as [[R. D. Laing]]) have argued that this leads to the diagnosis of delusions being based on the [[Subjectivity|subjective]] understanding of a particular psychiatrist, who may not have access to all the information that might make a belief otherwise interpretable. R. D. Laing's hypothesis has been applied to some forms of projective therapy to "fix" a delusional system so that it cannot be altered by the patient. Psychiatric researchers at [[Yale University]], [[Ohio State University]] and the Community Mental Health Center of Middle Georgia have used novels and motion picture films as the focus. Texts, plots and cinematography are discussed and the delusions approached tangentially.<ref>{{cite journal | vauthors = Giannini AJ |title=Use of fiction in therapy |journal=Psychiatric Times |volume=18 |issue=7 |pages=56 |year=2001 }}</ref> This use of fiction to decrease the malleability of a delusion was employed in a joint project by science-fiction author [[Philip Jose Farmer]] and Yale psychiatrist A. James Giannini. They wrote the novel ''[[Red Orc's Rage]]'', which, recursively, deals with delusional adolescents who are treated with a form of projective therapy. In this novel's fictional setting other novels written by Farmer are discussed and the characters are symbolically integrated into the delusions of fictional patients. This particular novel was then applied to real-life clinical settings.<ref>{{cite book | vauthors = Giannini AJ | chapter = Afterword | veditors = Farmer PJ | title = Red Orc's Rage | location = NY | publisher = Tor Books | date = 1991 | pages = 279–282 }}</ref>

Another difficulty with the diagnosis of delusions is that almost all of these features can be found in "normal" beliefs. Many religious beliefs hold exactly the same features, yet are not universally considered delusional. For instance, if a person was holding a true belief then they will of course persist with it. This can cause the disorder to be misdiagnosed by psychiatrists. These factors have led the psychiatrist [[Anthony David (neuropsychiatrist)|Anthony David]] to note that "there is no acceptable (rather than accepted) definition of a delusion."<ref>{{cite journal | vauthors = David AS |title=On the impossibility of defining delusions |journal=Philosophy, Psychiatry, & Psychology |volume=6 |issue=1 |pages=17–20 |year=1999 }}</ref> In practice, psychiatrists tend to diagnose a belief as delusional if it is either patently bizarre, causing significant distress, or excessively pre-occupying the patient, especially if the person is subsequently unswayed in belief by counter-evidence or reasonable arguments.{{cn|date=April 2025}}

Joseph Pierre, M.D. states that one factor that helps differentiate delusions from other kinds of beliefs is that anomalous subjective experiences are often used to justify delusional beliefs. While idiosyncratic and self-referential content often make delusions impossible to share with others,<ref>{{cite journal| vauthors = Aftab A |title=There and Back Again: Joseph Pierre, M.D. |journal=Psychiatric Times |volume=38 |issue=1 |year=2021 |url = https://www.psychiatrictimes.com/view/there-back-joseph-pierre}}</ref> Pierre suggests that it may be more helpful to emphasize the level of conviction, preoccupation, and extension of a belief rather than the content of the belief when considering whether a belief is delusional.<ref>{{cite journal | vauthors = Pierre JM | title = Faith or delusion? At the crossroads of religion and psychosis | journal = Journal of Psychiatric Practice | volume = 7 | issue = 3 | pages = 163–172 | date = May 2001 | pmid = 15990520 | doi = 10.1097/00131746-200105000-00004 | s2cid = 22897500 }}</ref>

It is important to distinguish true delusions from other symptoms such as [[anxiety]], [[fear]], or [[paranoia]]. To diagnose delusions a mental state examination may be used. This test includes [[Human physical appearance|appearance]], [[Mood (psychology)|mood]], affect, [[behavior]], rate and continuity of speech, evidence of hallucinations or abnormal beliefs, thought content, orientation to time, place and person, attention and [[Attentional control|concentration]], insight and judgment, as well as short-term [[memory]].<ref name="E">{{cite web|url=http://www.wrongdiagnosis.com/symptoms/delusions/tests.htm |title=Diagnostic Test List for Delusions |access-date=6 August 2010}}</ref>

Johnson-Laird suggests that delusions may be viewed as the natural consequence of failure to distinguish conceptual relevance. That is, irrelevant information would be framed as disconnected experiences, then it is taken to be relevant in a manner that suggests false causal connections. Furthermore, relevant information would be ignored as counterexamples.<ref name="F">{{cite journal | last1=Mujica-Parodi | first1=L.R. | last2=Sackeim | first2=Harold A. | title=Cultural Invariance and the Diagnosis of Delusions | journal=The Journal of Neuropsychiatry and Clinical Neurosciences | publisher=American Psychiatric Association Publishing | volume=13 | issue=3 | year=2001 | issn=0895-0172 | doi=10.1176/jnp.13.3.403-a |doi-access= | pages=403–409 }} See section "A New Definition of Delusional Ideation in Terms of Model Restriction".</ref>

===Definition===
Although non-specific concepts of madness have been around for several thousand years, the psychiatrist and philosopher [[Karl Jaspers]] was the first to define the four main criteria for a belief to be considered delusional in his 1913 book ''General Psychopathology''.<ref>{{Cite book |publisher = J. Springer |vauthors = Jaspers K |title = Allgemeine Psychopathologie: Ein Leitfaden für Studierende, Ärzte und Psychologen |location = Berlin |year = 1913}}</ref> These criteria are:
# certainty (held with absolute conviction)
# incorrigibility (not changeable by compelling counterargument or proof to the contrary)
# impossibility or falsity of content (implausible, bizarre, or patently untrue)<ref>{{harvnb|Jaspers|1997|p=106}}</ref>
# not amenable to understanding (i.e., belief cannot be explained psychologically)<ref>{{cite journal |vauthors = Walker C |title = Delusion: what did Jaspers really say? |journal = The British Journal of Psychiatry. Supplement |issue = 14 |pages = 94–103 |date = November 1991 |volume = 159 |doi = 10.1192/S0007125000296566 |pmid =1840789 |s2cid = 43018033 |url = https://pubmed.ncbi.nlm.nih.gov/1840789 }}</ref>

Furthermore, when beliefs involve value judgments, only those which cannot be proven true are considered delusions. For example: a man claiming that he flew into the [[Sun]] and flew back home. This would be considered a delusion,<ref name="A">{{cite web |url=http://www.abess.com/glossary.html#D |title=Terms in the Field of Psychiatry and Neurology |access-date=6 August 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100819071820/http://www.abess.com/glossary.html#D |archive-date=19 August 2010 }}</ref> unless he were speaking [[Literal and figurative language|figuratively]], or if the belief had a cultural or religious source. Only the first three criteria remain cornerstones of the current definition of a delusion in the [[DSM-5]].

Robert Trivers writes that delusion is a discrepancy in relation to objective reality, but with a firm conviction in reality of delusional ideas, which is manifested in the "affective basis of delusion".<ref>{{cite book | vauthors = Trivers R |date= 2002 |title= Natural Selection and Social Theory: Selected Papers of Robert Trivers.  |publisher= Oxford University Press  |isbn= 978-0-19-513062-1}}</ref>