Editing Psychosis (section)

=== Delusions ===
Psychosis may involve [[delusion]]al beliefs. A delusion is a ''fixed, false idiosyncratic belief'', which does not change even when presented with incontrovertible evidence to the contrary. Delusions are context- and culture-dependent: a belief that inhibits critical functioning and is widely considered delusional in one population may be common (and even adaptive) in another, or in the same population at a later time.<ref>{{cite book |last1=Joseph |first1=Shawn M. |last2=Siddiqui |first2=Waquar |title=StatPearls |date=2024 |publisher=StatPearls Publishing |url=https://www.ncbi.nlm.nih.gov/books/NBK539855/ |access-date=19 August 2024 |chapter=Delusional Disorder|pmid=30969677 }}</ref><ref>{{cite journal |last1=Ashinoff |first1=Brandon K. |last2=Singletary |first2=Nicholas M. |last3=Baker |first3=Seth C. |last4=Horga |first4=Guillermo |title=Rethinking delusions: A selective review of delusion research through a computational lens |journal=Schizophrenia Research |date=July 2022 |volume=245 |pages=23–41 |doi=10.1016/j.schres.2021.01.023 |pmid=33676820 |pmc=8413395 }}</ref> Since [[Norm (philosophy)|normative]] views may contradict available evidence, a belief need not contravene cultural standards in order to be considered delusional. However, the DSM-5 considers a belief delusional only if it is not widely accepted within a cultural or subcultural context.<ref>{{Citation |title=Schizophrenia Spectrum and Other Psychotic Disorders |date=2013-08-11 |work=DSM-5® Clinical Cases |url=https://doi.org/10.1176/appi.books.9781585624836.jb02 |access-date=2025-03-17 |publisher=American Psychiatric Publishing |doi=10.1176/appi.books.9781585624836.jb02 |isbn=978-1-58562-463-8}}</ref>

Prevalence in schizophrenia is generally considered at least 90%, and around 50% in bipolar disorder.

The DSM-5 characterizes certain delusions as "bizarre" if they are clearly implausible, or are incompatible with the surrounding cultural context. The concept of bizarre delusions has many criticisms, the most prominent being judging its presence is not highly reliable even among trained individuals.<ref name="Sadock Psychosis"/>

A delusion may involve diverse thematic content. The most common type is a [[persecutory delusion]], in which a person believes that an entity seeks to harm them. Others include [[delusions of reference]] (the belief that some element of one's experience represents a deliberate and specific act by or message from some other entity), [[delusions of grandeur]] (the belief that one possesses special power or influence beyond one's actual limits), [[thought broadcasting]] (the belief that one's thoughts are audible) and [[thought insertion]] (the belief that one's thoughts are not one's own). A delusion may also involve [[Delusional misidentification syndrome|misidentification]] of objects, persons, or environs that the afflicted should reasonably be able to recognize; such examples include [[Cotard's syndrome]] (the belief that oneself is partly or wholly [[dead]]) and [[clinical lycanthropy]] (the belief that oneself is or has transformed into an animal).

The subject matter of delusions seems to reflect the current culture in a particular time and location. For example, in the early 1900s in the United States, [[syphilis]] was a common theme in delusions. During the Second World War, it was Germany. In the [[Cold War]] era, communists became a frequent focus. Now, in recent years, technology is a common subject matter of delusions.<ref name="Cannon Kramer pp. 323–327">{{cite journal | vauthors = Cannon BJ, Kramer LM | title = Delusion content across the 20th century in an American psychiatric hospital | journal = The International Journal of Social Psychiatry | volume = 58 | issue = 3 | pages = 323–327 | date = May 2012 | pmid = 21421637 | doi = 10.1177/0020764010396413 | publisher = SAGE Publications | s2cid = 42421925 }}</ref> Some psychologists, such as those who practice the [[Open Dialogue]] method, believe that the content of psychosis represents an underlying thought process, that may in part, be responsible for psychosis,<ref name="Seikkula, Birgitta Alakare, Jukka A 2001 pp. 247–265">{{cite journal| vauthors = Seikkula J, Alakare B, Aaltonen J |title=Open Dialogue in Psychosis I: An Introduction and Case Illustration |journal=Journal of Constructivist Psychology |volume=14 |issue=4 |year=2001 |pages=247–265 |issn=1072-0537|doi=10.1080/10720530125965|s2cid=216136239 }}</ref> though the accepted medical position is that psychosis is due to a brain disorder.<ref>{{Cite journal |last=Saugstad |first=Letten F. |date=June 2008 |title=What is a psychosis and where is it located? |url=https://pubmed.ncbi.nlm.nih.gov/18516523/ |journal=European Archives of Psychiatry and Clinical Neuroscience |volume=258 Suppl 2 |pages=111–117 |doi=10.1007/s00406-008-2014-1 |issn=0940-1334 |pmid=18516523}}</ref>

Historically, [[Karl Jaspers]] classified psychotic delusions into ''primary'' and ''secondary'' types. Primary delusions are defined as arising suddenly and not being comprehensible in terms of normal mental processes, whereas secondary delusions are typically understood as being influenced by the person's background or current situation (e.g., ethnicity, religious, superstitious, or political beliefs).<ref name=Jaspers>{{cite book | vauthors = Jaspers K |author-link=Karl Jaspers | translator-last1 = Hoenig J, Hamilton M | language = German |title=Allgemeine Psychopathologie | trans-title = General Psychopathology |orig-year=1963 | edition = Reprint |date=1997-11-27 |publisher=Johns Hopkins University Press |location=Baltimore, Maryland |isbn=978-0-8018-5775-1}}</ref>