Editing Delusion (section)

==Causes==
{{See also|Psychosis#Causes|l1=Psychosis (causes)}}
Explaining the causes of delusions continues to be challenging and several theories have been developed.<ref>{{cite journal | vauthors = Kiran C, Chaudhury S | title = Understanding delusions | journal = Industrial Psychiatry Journal | volume = 18 | issue = 1 | pages = 3–18 | date = January 2009 | pmid = 21234155 | pmc = 3016695 | doi = 10.4103/0972-6748.57851 | doi-access = free }}</ref><ref>{{Cite book |last=McKenna |first=Peter |url=https://www.cambridge.org/core/product/identifier/9781139871785/type/book |title=Delusions: Understanding the Un-understandable |date=2017-07-25 |publisher=Cambridge University Press |isbn=978-1-139-87178-5 |edition=1 |doi=10.1017/9781139871785}}</ref> One is the [[Genetics|genetic]] or biological theory, which states that close relatives of people with delusional disorder are at increased risk of delusional traits. Another theory is the dysfunctional cognitive processing, which states that delusions may arise from distorted ways people have of explaining life to themselves. A third theory is called motivated or defensive delusions. This one states that some of those persons who are predisposed might experience the onset of delusional disorder in those moments when coping with life and maintaining high [[self-esteem]] becomes a significant challenge. In this case, the person views others as the cause of their personal difficulties in order to preserve a positive self-view.<ref name="H">{{cite web|url=http://www.minddisorders.com/Br-Del/Delusional-disorder.html |title=Delusional Disorder |access-date=6 August 2010}}</ref>

This condition is more common among people who have poor [[Hearing (sense)|hearing]] or [[Visual perception|sight]]. Also, ongoing stressors have been associated with a higher possibility of developing delusions. Examples of such stressors are [[immigration]], low socioeconomic status, and even possibly the accumulation of smaller daily struggles.<ref>{{cite journal | vauthors = Kingston C, Schuurmans-Stekhoven J | title = Life hassles and delusional ideation: Scoping the potential role of cognitive and affective mediators | journal = Psychology and Psychotherapy | volume = 89 | issue = 4 | pages = 445–463 | date = December 2016 | pmid = 26846698 | doi = 10.1111/papt.12089 }}</ref>

===Specific delusions===
The top two factors mainly concerned in the germination of delusions are disorder of brain functioning and background influences of temperament and personality.<ref>{{cite book | vauthors = Sims A |title=Symptoms in the mind: an introduction to descriptive psychopathology |publisher=W. B. Saunders |location=Philadelphia |year=2002 |pages=127 |isbn=0-7020-2627-1 }}</ref>

Higher levels of dopamine qualify as a sign of disorders of brain function. That they are needed to sustain certain delusions was examined by a preliminary study on delusional disorder (a psychotic syndrome) instigated to clarify if schizophrenia had a dopamine psychosis.<ref>{{cite journal | vauthors = Morimoto K, Miyatake R, Nakamura M, Watanabe T, Hirao T, Suwaki H | title = Delusional disorder: molecular genetic evidence for dopamine psychosis | journal = Neuropsychopharmacology | volume = 26 | issue = 6 | pages = 794–801 | date = June 2002 | pmid = 12007750 | doi = 10.1016/S0893-133X(01)00421-3 | doi-access = free }}</ref> There were positive results - delusions of jealousy and persecution had different levels of dopamine metabolite [[Homovanillic acid|HVA]] and [[homovanillyl alcohol]] (which may have been genetic). These can be only regarded as tentative results; the study called for future research with a larger population.

It is simplistic to say that a certain measure of dopamine will bring about a specific delusion. Studies show age<ref>{{cite journal | vauthors = Mazure CM, Bowers MB | title = Pretreatment plasma HVA predicts neuroleptic response in manic psychosis | journal = Journal of Affective Disorders | volume = 48 | issue = 1 | pages = 83–86 | date = February 1998 | pmid = 9495606 | doi = 10.1016/S0165-0327(97)00159-6 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Yamada N, Nakajima S, Noguchi T | title = Age at onset of delusional disorder is dependent on the delusional theme | journal = Acta Psychiatrica Scandinavica | volume = 97 | issue = 2 | pages = 122–124 | date = February 1998 | pmid = 9517905 | doi = 10.1111/j.1600-0447.1998.tb09973.x | s2cid = 39266698 }}</ref> and gender to be influential and it is most likely that HVA levels change during the life course of some syndromes.<ref>{{cite journal | vauthors = Tamplin A, Goodyer IM, Herbert J | title = Family functioning and parent general health in families of adolescents with major depressive disorder | journal = Journal of Affective Disorders | volume = 48 | issue = 1 | pages = 1–13 | date = February 1998 | pmid = 9495597 | doi = 10.1016/S0165-0327(97)00105-5 }}</ref>

On the influence of personality, it has been said: "Jaspers considered there is a subtle change in personality due to the illness itself; and this creates the condition for the development of the delusional atmosphere in which the delusional intuition arises."<ref>{{cite book | vauthors = Sims A |title=Symptoms in the mind: an introduction to descriptive psychopathology |publisher=W. B. Saunders |location=Philadelphia |year=2002 |pages=128 |isbn=0-7020-2627-1 }}</ref>

Cultural factors have "a decisive influence in shaping delusions".<ref>{{cite journal | vauthors = Draguns JG, Tanaka-Matsumi J | title = Assessment of psychopathology across and within cultures: issues and findings | journal = Behaviour Research and Therapy | volume = 41 | issue = 7 | pages = 755–776 | date = July 2003 | pmid = 12781244 | doi = 10.1016/S0005-7967(02)00190-0 }}</ref> For example, delusions of guilt and punishment are frequent in a Western, Christian country like Austria, but not in Pakistan, where it is more likely persecution.<ref>{{cite journal | vauthors = Stompe T, Friedman A, Ortwein G, Strobl R, Chaudhry HR, Najam N, Chaudhry MR | title = Comparison of delusions among schizophrenics in Austria and in Pakistan | journal = Psychopathology | volume = 32 | issue = 5 | pages = 225–234 | year = 1999 | pmid = 10494061 | doi = 10.1159/000029094 | s2cid = 25376490 }}</ref> Similarly, in a series of case studies, delusions of guilt and punishment were found in Austrian patients with Parkinson's being treated with l-dopa, a dopamine agonist.<ref>{{cite journal | vauthors = Birkmayer W, Danielczyk W, Neumayer E, Riederer P | title = The balance of biogenic amines as condition for normal behaviour | journal = Journal of Neural Transmission | volume = 33 | issue = 2 | pages = 163–178 | year = 1972 | pmid = 4643007 | doi = 10.1007/BF01260902 | s2cid = 28152591 }}</ref>