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{{Infobox_Disease |
__NOTOC__
  Name          = Psychosis |
  Image          = |
  Caption        = |
  DiseasesDB    = |
  ICD10          = |
  ICD9          = {{ICD9|290}}-{{ICD9|299}} |
  ICDO          = |
  OMIM          = 603342 |
  OMIM_mult      = {{OMIM2|608923}} {{OMIM2|603175}} {{OMIM2|192430}}|
  MedlinePlus    = 001553 |
  eMedicineSubj  = |
  eMedicineTopic = |
  MeshName      = Psychotic+Disorders |
  MeshNumber    = F03.700.675 |
}}


{{SI}}


{{CMG}}
{{Psychosis}}


{{Editor Help}}
{{CMG}}; {{AE}}{{Vbe}} Somal Khan, MD  {{KS}}


==Overview==
{{SK}} Acute and transient [[Psychotic Disorder|psychotic]] disorders; acute polymorphic [[Psychotic Disorder|psychotic]] disorder; [[anxiety]] bliss psychosis; anxiety elation psychosis; anxiety happiness psychosis; atypical psychosis; [[bipolar]] psychosis; brief psychotic disorder; brief reactive psychosis; cycloid psychosis; good [[prognosis]] [[schizophrenia]]; hysterical psychosis; [[mood]] disturbances; mood disorders; psychogenic psychosis; reactive schizophrenia; [[schizophrenia]]; schizophrenia spectrum; [[Schizophreniform disorder|schizophreniform]] disorder; [[Schizoaffective Disorder|schizoaffective]] disorder; stress psychosis; substance induced psychosis; thought disturbances; transient psychosis
'''Psychosis''' is a generic [[psychiatry|psychiatric]] term for a [[Mental status examination|mental state]] often described as involving a "loss of contact with reality". ''Stedman's Medical Dictionary'' defines psychosis as "a severe mental disorder, with or without organic damage, characterized by derangement of personality and loss of contact with reality and causing deterioration of normal social functioning."<ref>{{cite web | url = http://www.kmle.com/search.php?Search=psychosis | title = ''KMLE Medical Dictionary Definition of psychosis'' | author = [http://www.kmle.com The American Heritage Stedman's Medical Dictionary]}}</ref>


People experiencing a psychotic episode may report [[hallucination]]s or [[delusion|delusional beliefs]] (e.g., grandiose or [[paranoia|paranoid]] delusions), and may exhibit [[Wiktionary:personality|personality]] changes and [[thought disorder|disorganized thinking]]. This is often accompanied by [[anosognosia|lack of insight]] into the unusual or bizarre nature of their behaviour, as well as difficulty with social interaction and impairment in carrying out the activities of daily living.
==[[Psychosis overview|Overview]]==


A wide variety of nervous system stressors, both organic and functional, can cause a psychotic reaction. This has led to the belief that psychosis is the 'fever' of mental illness&mdash;a serious but nonspecific indicator.<ref name=Tsuang_et_al_2000/><ref name=DELAGE_1995>{{cite journal | last = DeLage | first = J. | year = 1955 | month = February | title = [Moderate psychosis caused by mumps in a child of nine years.] | journal = Laval Médical | volume = 20 | issue = 2 | pages = 175-183 | id = {{PMID|14382616}}}}</ref>
==[[Psychosis historical perspective|Historical Perspective]]==


However, most people have unusual and reality-distorting experiences at some point in their lives, without being impaired or even distressed by these experiences. For example, many people have experienced [[vision]]s of some kind, and some have even found [[inspiration]] or religious revelation in them.<ref>Dick, P.K. (1981) ''[[VALIS]]''. London: Gollancz. ISBN 0-679-73446-5</ref> As a result, it has been argued that psychosis is not fundamentally separate from normal consciousness, but rather, is on a continuum with normal consciousness.<ref name=Johns_2001>{{cite journal| last = Johns | first = Louise C. | authorlink = | coauthors = Jim van Os | title = The continuity of psychotic experiences in the general population.
==[[Psychosis classification|Classification]]==
| journal = Clinical Psychology Review| volume = 21| issue = 8| pages = 1125-41| publisher = PubMed| year = 2001| url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=pubmed_Abstract&cmd=Retrieve&db=pubmed&list_uids=11702510&dopt=ExternalLink| doi = 10.1016/S0272-7358(01)00103-9 | id = {{PMID|11702510}} | accessdate = 2006-08-19 }}</ref> In this view, people who are clinically found to be psychotic, may simply be having particularly intense or distressing experiences (see [[schizotypy]]).


In pop culture, the term "psychotic" is often used incorrectly to refer to [[psychopathy]].
==[[Psychosis pathophysiology|Pathophysiology]]==


==History==
==[[Psychosis causes|Causes]]==
The word ''psychosis'' was first used by Ernst von Feuchtersleben in 1845<ref> {{cite journal| last = Beer| first = M D | authorlink = | coauthors = | title = Psychosis: from mental disorder to disease concept. | journal = Hist Psychiatry| volume = 6| issue = 22(II)| pages = 177-200| publisher = PubMed| date = 1995| url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=Display&DB=pubmed| doi = | id = PMID 11639691| accessdate = 2006-08-19 }}</ref> as an alternative to [[insanity]] and [[mania]] and stems from the Greek ''psyche'' (soul) and ''-osis'' (diseased or abnormal condition).<ref>{{cite web| last = | first = | authorlink = | coauthors = | title = Online Etymology Dictionary| work = | publisher = Douglas Harper| date = 2001| url = http://www.etymonline.com/index.php?search=psychosis&searchmode=none| format = | doi = | accessdate = 2006-08-19 }}</ref> The word was used to distinguish disorders which were thought to be disorders of the mind, as opposed to [[neurosis]], which was thought to stem from a disorder of the nervous system.


The division of the major psychoses into manic depressive insanity (now called [[bipolar disorder]]) and dementia praecox (now called [[schizophrenia]]) was made by [[Emil Kraepelin]], who attempted to create a synthesis of the various mental disorders identified by 19th century [[Psychiatry|psychiatrists]], by grouping diseases together based on classification of common symptoms. Kraepelin used the term 'manic depressive insanity' to describe the whole spectrum of [[mood disorder]]s, in a far wider sense than it is usually used today. In Kraepelin's classification this would include 'unipolar' [[clinical depression]], as well as bipolar disorder and other mood disorders such as [[cyclothymia]]. These are characterised by problems with mood control and the psychotic episodes appear associated with disturbances in mood, and patients will often have periods of normal functioning between psychotic episodes even without medication. [[Schizophrenia]] is characterized by psychotic episodes which appear to be unrelated to disturbances in mood, and most non-medicated patients will show signs of disturbance between psychotic episodes.
==[[Psychosis differential diagnosis|Differentiating Psychosis from other Disorders]]==


During the 1960s and 1970s, psychosis was of particular interest to [[counterculture]] critics of mainstream psychiatric practice, who argued that it may simply be another way of constructing reality and is not necessarily a sign of illness. For example, [[R. D. Laing]] argued that psychosis is a symbolic way of expressing concerns in situations where such views may be unwelcome or uncomfortable to the recipients. He went on to say that psychosis could be also seen as a transcendental experience with healing and spiritual aspects. [[Thomas Szasz]] focused on the social implications of labelling people as psychotic; a label he argues unjustly medicalises different views of reality so such unorthodox people can be controlled by society. Psychoanalysis has a detailed account of psychosis which differs markedly from Psychiatry. Freud and Lacan outlined their perspective on the structure of psychosis in a number of works [http://gamahucherpress.yellowgum.com/books/psychoanalysis/F_PSYCHOSIS.pdf Lacan and Freud on the structure of psychosis :]
==[[Psychosis epidemiology and demographics|Epidemiology and Demographics]]==


In medical practice today, a descriptive approach to psychosis (and to all mental illness) is used, based on [[behavioral]] and [[clinical]] observations. This approach is adopted in the standard guide to psychiatric diagnoses employed in the United States, the [[Diagnostic and Statistical Manual of Mental Disorders]] (DSM). Since the DSM provides a widely-used standard of reference, the description presented here will largely reflect that point of view.
==[[Psychosis risk factors|Risk Factors]]==


==Classification==
==[[Psychosis screening|Screening]]==
According to the [[Diagnostic and Statistical Manual of Mental Disorders|DSM]], psychosis can be a [[symptom]] of mental illness, but it is not a mental illness in its own right. For example, people with [[schizophrenia]] often experience psychosis, but so can people with [[bipolar disorder]] (manic depression), [[Clinical depression|unipolar depression]], [[delirium]], or drug [[withdrawal]].<ref>American Psychiatric Association. ''Diagnostic and Statistical Manual of Mental Disorders, Fourth edition - Text Revision'' (Published by the American Psychiatric Association, 2000).</ref><ref name=Tsuang_et_al_2000> {{cite journal | last = Tsuang | first = Ming T. | authorlink = | coauthors = William S. Stone, Stephen V. Faraone | year = 2000 | month = July | title = Toward Reformulating the Diagnosis of Schizophrenia | journal = American Journal of Psychiatry | volume = 157| issue = 7 | pages = 1041-1050 | url = http://ajp.psychiatryonline.org/cgi/content/full/157/7/1041 | id = {{PMID|10873908}} | accessdate = 2006-08-19 }}</ref> People diagnosed with these conditions can also have long periods ''without'' psychosis. Conversely, psychosis can occur in people who do not have chronic mental illness (e.g. due to an adverse drug reaction or extreme stress).<ref name=Jaunch_1988>{{cite journal | last = Jauch | first = D. A. | coauthors = William T. Carpenter, Jr. | year = 1988 | month = February | title = Reactive psychosis. I. Does the pre-DSM-III concept define a third psychosis? | journal = Journal of Nervous and Mental Disease | volume = 176 | issue = 2 | pages = 72-81 | id = {{PMID|3276813}}}}</ref>


Psychosis should be distinguished from [[insanity]], which is a legal term denoting that a person is not criminally responsible for his or her actions.<ref>Jacobson J.L. and A.M. Jacobson, eds. ''Psychiatric Secrets'' (Philadelphia: Hanley and Belfus, 2001)</ref>
==[[Psychosis natural history, complications and prognosis|Natural History, Complications, and Prognosis]]==
 
==Diagnosis==
Psychosis should be distinguished from [[psychopathy]], a [[personality disorder]] associated with violence, lack of [[empathy]] and socially manipulative behavior.<ref name=hare1>Hare, R. D. [http://www.psychiatrictimes.com/p960239.html Psychopathy and Antisocial Personality Disorder: A Case of Diagnostic Confusion, Psychiatric Times, February 1996, XIII, Issue 2] Accessed [[June 26]], [[2006]]</ref> Despite both being colloquially abbreviated "psycho", psychosis bears little similarity to the core features of psychopathy, particularly with regard to violence, which rarely occurs in psychosis,<ref name=Milton_et_al_2001>{{cite journal | last = Milton | first = John | coauthors = Shazad Amin, Swaran P. Singh, Glynn Harrison, Peter Jones, Tim Croudace, Ian Medley, and John Brewin | year = 2001 | month = May | title = Aggressive incidents in first-episode psychosis | journal = British Journal of Psychiatry | volume = 178 | pages = 433-440 | id = {{PMID|11331559}} | url = http://bjp.rcpsych.org/cgi/content/full/178/5/433 | accessdate = 2006-10-21}}</ref><ref name=Foley_et_al_2005>{{cite journal | last = Foley | first =  Sharon R. | coauthors = Brendan D. Kelly, Mary Clarke, Orfhlaith McTigue, Maurice Gervin, Moyyad Kamali, Conall Larkin, Eadbhard O'Callaghan, and Stephen Browne | date = [[January 1]], [[2005]] | title = Incidence and clinical correlates of aggression and violence at presentation in patients with first episode psychosis | journal = Schizophrenia Research | volume = 72 | issue = 2-3 | pages = 161-168 | doi = 10.1016/j.schres.2004.03.010 | id = {{PMID|15560961}} | url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=pubmed_Abstract&cmd=Retrieve&db=pubmed&list_uids=15560961&dopt=ExternalLink | accessdate = 2006-10-21}}</ref> and distorted perception of reality, which rarely occurs in psychopathy.<ref name=Nestor_et_al_2002>{{cite journal | last = Nestor | first = Paul G. | coauthors = Matthew Kimble, Ileana Berman, and Joel Haycock | year = 2002 | month = January | title = Psychosis, Psychopathy, and Homicide: A Preliminary Neuropsychological Inquiry | journal = American Journal of Psychiatry | volume = 159 | issue = 1 | pages = 138-140 | id = {{PMID|11772704}} | url = http://ajp.psychiatryonline.org/cgi/content/full/159/1/138 | accessdate = 2006-10-21}}</ref>
[[Psychosis history and symptoms|History and Symptoms]] | [[Psychosis physical examination|Physical Examination]] | [[Psychosis laboratory findings|Laboratory Findings]] | [[Psychosis electroencephalogram|Electroencephalogram]] | [[Psychosis other diagnostic studies|Other Diagnostic Studies]]
 
Psychosis should also be distinguished from [[delirium]]: a psychotic individual may be able to perform actions that require a high level of intellectual effort in clear consciousness, whereas a delirious individual will have impaired memory and cognitive function.
 
==Causes==
Causes of mental illness are customarily distinguished as "organic" or "functional". Organic causes are those for which a medical, [[pathophysiology|pathophysiological]] basis can be found. Functional causes are "the rest", the psychological causes properly speaking, e.g. anxiety, depression, etc.
 
===="Functional" causes====
Functional causes of psychosis include the following:
*[[schizophrenia]]
*[[bipolar disorder]] (manic depression)
*severe [[clinical depression]]
*severe [[psychosocial]] [[Stress (medicine)|stress]]
*[[sleep deprivation]]
 
A psychotic episode can be significantly affected by mood. For example, people experiencing a psychotic episode in the context of depression may experience persecutory or self-blaming delusions or hallucinations, while people experiencing a psychotic episode in the context of mania may form grandiose delusions.
 
Stress is known to contribute to and trigger psychotic states. A history of psychologically traumatic events, and the recent experience of a stressful event, can both contribute to the development of psychosis. Short-lived psychosis triggered by stress is known as [[brief reactive psychosis]], and patients may spontaneously recover normal functioning within two weeks.<ref name=Jaunch_1988/> In some rare cases, individuals may remain in a state of full-blown psychosis for many years, or perhaps have attenuated psychotic symptoms (such as low intensity hallucinations) present at most times.
 
Sleep deprivation has been linked to psychosis.<ref name=sleep_dep1>{{cite journal | last = Sharma | first = Verinder | coauthors = Dwight Mazmanian | year = 2003 | month = April | title = Sleep loss and postpartum psychosis | journal = Bipolar Disorders | volume = 5 | issue = 2 | pages = 98-105 | id = {{PMID|12680898}} | doi = 10.1034/j.1399-5618.2003.00015.x | url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=pubmed_Citation&cmd=Retrieve&db=pubmed&list_uids=12680898&dopt=ExternalLink | accessdate = 2006-09-27}}</ref><ref name=sleep_dep2>{{cite journal | last = Chan-Ob | first = T. | coauthors = V. Boonyanaruthee | year = 1999 | month = September | title = Meditation in association with psychosis | journal = Journal of the Medical Association of Thailand | volume = 82 | issue = 9 | pages = 925-930 | id = {{PMID|10561951}}}}</ref><ref name=sleep_dep3>{{cite journal | last = Devillieres | first = P. | coauthors = M. Opitz, P. Clervoy, and J. Stephany | year = 1996 | month = May-June | title = [Delusion and sleep deprivation] | journal = L'Encéphale | volume = 22 | issue = 3 | pages = 229-231 | id = {{PMID|}}}}</ref> However, this is not a risk for most people, who merely experience [[hypnagogia|hypnagogic]] or [[hypnopompic]] hallucinations, i.e. unusual sensory experiences or thoughts that appear during waking or drifting off to sleep. These are normal sleep phenomena and are not considered signs of psychosis.<ref name=Ohayon_et_al_1996>{{cite journal | last = Ohayon | first = M. M. | coauthors = R. G. Priest, M. Caulet, and C. Guilleminault | year = 1996 | month = October | title = Hypnagogic and hypnopompic hallucinations: pathological phenomena? | journal = British Journal of Psychiatry | volume = 169 | issue = 4 | pages = 459-467 | id = {{PMID|8894197}} | url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=pubmed_Abstract&cmd=Retrieve&db=pubmed&list_uids=8894197&dopt=ExternalLink | accessdate = 2006-10-21}}</ref>
 
===="Organic" causes====
Psychosis arising from "organic" (non-psychological) conditions is sometimes known as '''secondary psychosis'''. It can be associated with the following [[pathology|pathologies]]:
*neurological disorders, including:
**[[brain tumour]]<ref name=Brain_tumor>{{cite journal | last = Lisanby | first = S. H. | coauthors =  C. Kohler, C. L. Swanson, and R. E. Gur | year = 1998 | month = January | title = Psychosis Secondary to Brain Tumor | journal = Seminars in clinical neuropsychiatry | volume = 3 | issue = 1 | pages = 12-22 | id = {{PMID|10085187}} }}</ref>
**[[dementia with Lewy bodies]]<ref name=DLB>{{cite journal | last = McKeith | first = Ian G. | year = 2002 | month = February | title = Dementia with Lewy bodies | journal = British Journal of Psychiatry | volume = 180 | pages = 144-147 | id = {{PMID|11823325}} | url = http://bjp.rcpsych.org/cgi/content/full/180/2/144 | accessdate = 2006-09-27}}</ref>
**[[multiple sclerosis]]<ref name=multiple_sclerosis>{{es icon}} {{cite journal | last = Rodriguez Gomez | first = Diego | coauthors = Elvira Gonzalez Vazquez and Óscar Perez Carral | date = [[August 16]]-31, 2005 | title = Psicosis aguda como inicio de esclerosis multiple / Acute psychosis as the presenting symptom of multiple sclerosis / Psicose aguda como inicio de esclerose multipla | journal = Revista de Neurología | volume = 41 | issue = 4 | pages = 255-256 | id = {{PMID|16075405}} | url = http://www.revneurol.com/LinkOut/formMedLine.asp?Refer=2005320&Revista=RevNeurol | accessdate = 2006-09-27}} </ref>
**[[sarcoidosis]]<ref name=Sarcoidosis>{{cite journal | last = Bona | first = Joseph R. | coauthors = Sondralyn M. Fackler, Morris J. Fendley and Charles B. Nemeroff | year = 1998 | month = August | title = Neurosarcoidosis as a Cause of Refractory Psychosis: A Complicated Case Report | journal = American Journal of Psychiatry | volume = 155 | issue = 8 | pages = 1106-1108 | id = {{PMID|9699702}} | url = http://www.ajp.psychiatryonline.org/cgi/content/full/155/8/1106 | accessdate = 2006-09-29 }}</ref>
**[[Lyme Disease]]<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=7943444&query_hl=53&itool=pubmed_docsum]
Fallon BA, Nields JA. "Lyme disease: a neuropsychiatric illness". Am J Psychiatry. 1994 Nov;151(11):1571-83.</ref><ref>Hess A, Buchmann J, Zettl UK, Henschel S, Schlaefke D, Grau G, Benecke R."Borrelia burgdorferi central nervous system infection presenting as an organic schizophrenialike disorder". Biol Psychiatry. 1999 Mar 15;45(6):795.</ref><ref>van den Bergen HA, Smith JP, van der Zwan A. "Lyme psychosis". Ned Tijdschr Geneeskd. 1993 Oct 9;137(41):2098-100.</ref>
**[[syphilis]] <ref>Kararizou E, Mitsonis C, Dimopoulos N, Gkiatas K, Markou I, Kalfakis N. "Psychosis or simply a new manifestation of neurosyphilis?" J Int Med Res. 2006 May-Jun;34(3):335-7.</ref><ref>Brooke D, Jamie P, Slack R, Sulaiman M, Tyrer P. "Neurosyphilis--a treatable psychosis". Br J Psychiatry. 1987 Oct;151:556.</ref> 
**[[Alzheimer's Disease]]<ref>Lesser JM, Hughes S. "Psychosis-related disturbances. Psychosis, agitation, and disinhibition in Alzheimer's disease: definitions and treatment options." Geriatrics. 2006 Dec;61(12):14-20. Review.</ref>
**[[Parkinson's Disease]]<ref>Wedekind S."Depressive syndrome, psychoses, dementia: frequent manifestations in Parkinson disease" MMW Fortschr Med. 2005 Jun 2;147(22):11. German.</ref>
 
*electrolyte disorders such as:
**[[hypocalcemia]]<ref name=Rossman_1956>{{cite journal | last = Rossman | first = Phillip L. | coauthors = Robert M. Vock | year = 1956 | month = September | title = Postpartum Tetany and Psychosis Due to Hypocalcemia | journal = California Medicine | volume = 85 | issue = 3 | pages = 190-193 | id = {{PMID|13356186}} | url = http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1531921&blobtype=pdf | format = PDF | accessdate = 2006-10-16 }}</ref>
**[[hypernatremia]]<ref name=Jana_1973>{{cite journal | last = Jana | first = D. K. | coauthors = L. Romano-Jana | year = 1973 | month = October | title = Hypernatremic psychosis in the elderly: case reports | journal = Journal of the American Geriatrics Society | volume = 21 | issue = 10 | pages = 473-477 | id = {{PMID|4729012}}}}</ref>
**[[hyponatremia]]<ref name=Haensch_et_al_1996>{{cite journal | last = Haensch | first = C. A. | coauthors = G. Hennen and J. Jorg | year = 1996 | month = April | title = [Reversible exogenous psychosis in thiazide-induced hyponatremia of 97 mmol/l] | journal = Der Nervenarzt | volume = 67 | issue = 4 | pages = 319-322 | id = {{PMID|8684511}}}}</ref>
**[[hypokalemia]]<ref name=Hafez_et_al_1984>{{cite journal | last = Hafez | first = H. | coauthors = J. S. Strauss, M. D. Aronson, and C. Holt | year = 1984 | month = June | title = Hypokalemia-induced psychosis in a chronic schizophrenic patient | journal = Journal of Clinical Psychiatry | volume = 45 | issue = 6 | pages = 277-279 | id = {{PMID|6725222}}}}</ref>
**[[hypomagnesemia]]<ref name=Konstantakos_2006>{{cite web | url = http://www.emedicine.com/ped/topic1122.htm | title = Hypomagnesemia | accessmonthday = [[October 16]] | accessyear = [[2006]] | last = Konstantakos | first = Anastasios K. | coauthors = Enrique Grisoni | date = [[May 25]], [[2006]] | work = eMedicine | publisher = WebMD}}</ref>
**[[hypermagnesemia]]<ref name=Velasco_et_al_1999>{{cite journal | last = Velasco | first = P. Joel | coauthors = Manoochehr Manshadi, Kevin Breen, and Steven Lippmann | year = 1999 | month = December | title = Psychiatric Aspects of Parathyroid Disease | journal = Psychosomatics | volume = 40 | issue = 6 | pages = 486-490 | id = {{PMID|10581976}} | url = http://psy.psychiatryonline.org/cgi/content/full/40/6/486 | accessdate = 2006-10-17}}</ref> 
**[[hypercalcemia]]<ref name=Rosenthal_et_al_1997>{{cite journal | last = Rosenthal | first = M. | coauthors = I. Gil and B. Habot | year = 1997 | title = Primary hyperparathyroidism: neuropsychiatric manifestations and case report | journal = Israel Journal of Psychiatry and Related Sciences | volume = 34 | issue = 2 | pages = 122-125 | id = {{PMID|9231574}}}}</ref> 
**[[hypophosphatemia]]<ref name=Nanji_1984>{{cite journal | last = Nanji | first = A. A. | year = 1984 | month = November | title = The psychiatric aspect of hypophosphatemia | journal = Canadian Journal of Psychiatry | volume = 29 | issue = 7 | pages = 599-600 | id = {{PMID|6391648}}}}</ref>
*[[hypoglycemia]]<ref name=hypoglycemia>{{cite online journal | last = Padder | first = Tanveer | coauthors = Aparna Udyawar, Nouman Azhar, and Kamil Jaghab | year = 2005 | month = December | title = Acute Hypoglycemia Presenting as Acute Psychosis | journal = Psychiatry online | url = http://www.priory.com/psych/hypg.htm | accessdate = 2006-09-27}}</ref>
*[[Systemic Lupus Erythematosus|lupus]]<ref name=Lupus_Psychosis_India>{{cite journal | last = Robert | first = M. | coauthors = R. Sunitha, and N. K. Thulaseedharan | year = 2006 | month = March | title = Neuropsychiatric manifestations systemic lupus erythematosus: A study from South India | journal = Neurology India | volume = 54 | issue = 1 | pages = 75-77 | id = {{PMID|16679649}} | url = http://www.neurologyindia.com/article.asp?issn=0028-3886;year=2006;volume=54;issue=1;spage=75;epage=77;aulast=Robert | accessdate = 2006-09-29 }}</ref>
*[[AIDS]]<ref name=>{{cite book | last = Evans | first = Dwight L. | coauthors = Karen I. Mason, Jane Leserman, Russell Bauer And John Petitto | editor = Kenneth L Davis, Dennis Charney, Joseph T Coyle, Charles Nemeroff | title = Neuropsychopharmacology: The Fifth Generation of Progress | url = http://www.acnp.org/default.aspx?Page=5thGenerationChapters | accessdate = 2006-10-16 | edition = 5th | date = 2002-02-01 | publisher = Lippincott Williams & Wilkins | location = Philadelphia | id = ISBN 0-7817-2837-1 | pages = 1281-1301 | chapter = Chapter 90: Neuropsychiatric Manifestations of HIV-1 Infection and AIDS | chapterurl = http://www.acnp.org/g4/GN401000149/CH146.html }}</ref>
*[[leprosy]]<ref name=Lowinger_1959>{{cite journal | last = Lowinger | first = Paul | year = 1959 | month = July | title = LEPROSY AND PSYCHOSIS | journal = American Journal of Psychiatry | volume = 116 | issue = 1 | pages = 32-37 | doi = 10.1176/appi.ajp.116.1.32 | id = {{PMID|}} | url = http://ajp.psychiatryonline.org/cgi/content/abstract/116/1/32 | accessdate = 2006-10-17}}</ref><ref name=Ponomareff_1965>{{cite journal | last = Ponomareff | first = G. L. | year = 1965 | month = June | title = PHENOMENOLOGY OF DELUSIONS IN A CASE OF LEPROSY | journal = American Journal of Psychiatry | volume = 121 | issue = 12 | pages = 1211 | id = {{PMID|14286061}} | url = http://ajp.psychiatryonline.org/cgi/reprint/121/12/1211 | format = PDF | accessdate = 2006-10-17}}</ref>
*[[malaria]]<ref name=Tilluckdharry_et_al_1996>{{cite journal | last = Tilluckdharry | first = C. C. | coauthors = D. D. Chaddee, R. Doon, and J. Nehall | year = 1996 | month = March | title = A case of vivax malaria presenting with psychosis | journal = West Indian Medical Journal | volume = 45 | issue = 1 | pages = 39-40 | id = {{PMID|8693739}}}}</ref>
*Adult-onset [[vanishing white matter leukoencephalopathy]]<!--
 
--><ref name="pmid17470759">{{cite journal |author=Denier C, Orgibet A, Roffi F, Jouvent E, Buhl C, Niel F, Boespflug-Tanguy O, Said G, Ducreux D |title=Adult-onset vanishing white matter leukoencephalopathy presenting as psychosis |journal=Neurology |volume=68 |issue=18 |pages=1538-9 |year=2007 |pmid=17470759 |doi=10.1212/01.wnl.0000260701.76868.44}}</ref><!--
 
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*Late-onset [[metachromatic leukodystrophy]]<!--
 
--><ref name="pmid9411279">{{cite journal |author=Hermle L, Becker FW, Egan PJ, Kolb G, Wesiack B, Spitzer M |title=[Metachromatic leukodystrophy simulating schizophrenia-like psychosis] |language=German |journal=Der Nervenarzt |volume=68 |issue=9 |pages=754-8 |year=1997 |pmid=9411279 |doi=}}</ref><ref name="pmid12928504">{{cite journal |author=Black DN, Taber KH, Hurley RA |title=Metachromatic leukodystrophy: a model for the study of psychosis |journal=The Journal of neuropsychiatry and clinical neurosciences |volume=15 |issue=3 |pages=289-93 |year=2003 |pmid=12928504 |doi=}}[http://neuro.psychiatryonline.org/cgi/content/full/15/3/289 free full text]</ref><ref name="pmid15644995">{{cite journal |author=Kumperscak HG, Paschke E, Gradisnik P, Vidmar J, Bradac SU |title=Adult metachromatic leukodystrophy: disorganized schizophrenia-like symptoms and postpartum depression in 2 sisters |journal=Journal of psychiatry & neuroscience : JPN |volume=30 |issue=1 |pages=33-6 |year=2005 |pmid=15644995 |doi=}}[http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=543838 free full text]</ref><!--
 
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Psychosis can even be caused by apparently innocuous ailments such as [[flu]]<ref name=Steinberg_et_al_1959>{{cite journal | last = Steinberg | first = D. | coauthors = S. R. Hirsch, S. D. Marston, K. Reynolds, and R. N. Sutton | year = 1972 | month = May | title = Influenza infection causing manic psychosis | journal = British Journal of Psychiatry | volume = 120 | issue = 558 | pages = 531-535 | id = {{PMID|5041533}}}}</ref><ref name=Maurizi_1985>{{cite journal | last = Maurizi | first = C. P. | year = 1985 | month = February | title = Influenza and mania: a possible connection with the locus ceruleus | journal = Southern Medical Journal | volume = 78 | issue = 2 | pages = 207-209 | id = {{PMID|3975719}}}}</ref> or [[mumps]].<ref name=Keddie_1965>{{cite journal | last = Keddie | first = K. M. | year = 1965 | month = August | title = Toxic psychosis following mumps | journal = British Journal of Psychiatry | volume = 111 | pages = 691-696 | id = {{PMID|14337417}}}}</ref>
 
====Psychoactive drugs====
Psychotic states may occur with [[Psychoactive drug]] [[intoxication]] or [[withdrawal]]. Drugs whose use, abuse or withdrawal are implicated include:
*[[ethanol|alcohol]]<ref name=alcohol>{{cite web | url = http://www.emedicine.com/med/topic3113.htm | title = Alcohol-Related Psychosis |accessmonthday = [[September 27]] | accessyear = 2006 | last = Larson | first = Michael | date = 2006-03-30 | work = eMedicine | publisher = WebMD}}</ref><ref name=>{{cite journal | last = Soyka | first = Michael | year = 1990 | month = March | title = Psychopathological characteristics in alcohol hallucinosis and paranoid schizophrenia. | journal = Acta Psychiatrica Scandanavica | volume = 81 | issue = 3 | pages = 255-9 | id = {{PMID|2343749}}}}</ref><ref name=Gossman_2005>{{cite web | url = http://www.emedicine.com/EMERG/topic123.htm | title = Delirium Tremens | accessmonthday = October 16 | accessyear = 2006 | last = Gossman | first = William | date = November 19, 2005 | work = eMedicine | publisher = WebMD}}</ref>
*OTC drugs, such as:
**[[Dextromethorphan]]
**Certain [[antihistamine]]s at high doses.<ref name=diphenhydramine_trip_therapeutic>{{cite journal | last = Sexton | first = J. D. | coauthors = D. J. Pronchik | year = 1997 | month = September | title = Diphenhydramine-induced psychosis with therapeutic doses | journal = American Journal of Emergency Medicine | volume = 15 | issue = 5 | pages = 548-549 | id = {{PMID|9270406}} | url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=pubmed_AbstractPlus&cmd=Retrieve&db=pubmed&list_uids=9270406&dopt=ExternalLink | accessdate = 2006-09-29}}</ref><ref name=diphenhydramine_trip_supratherapeutic>{{cite journal | last = Lang | first = K. | coauthors = H. Sigusch, and S. Muller | date = [[December 8]], [[1995]] | title = [An anticholinergic syndrome with hallucinatory psychosis after diphenhydramine poisoning] | journal = Deutsche medizinische Wochenschrift | volume = 120 | issue = 49 | pages = 1695-1698 | id = {{PMID|7497894}}}}</ref><ref name=diphenhydramine_poisoning_psychosis>{{cite journal | last = Schreiber | first = W. | coauthors = A. M. Pauls and J. C. Kreig | date = [[February 5]], [[1988]] | title = [Toxic psychosis as an acute manifestation of diphenhydramine poisoning] | journal = Deutsche medizinische Wochenschrift | volume = 113 | issue = 5 | pages = 180-183 | id = {{PMID|3338401}}}}</ref><ref name=Promethazine>{{cite journal | last = Timnak | first = Charles | coauthors = Ondria Gleason | year = 2004 | month = January-February | title = Promethazine-Induced Psychosis in a 16-Year-Old Girl | journal = Psychosomatics | volume = 45 | issue = 1 | pages = 89-90 | id = {{PMID|14709767}} | url = http://psy.psychiatryonline.org/cgi/content/full/45/1/89 | accessdate = 2006-09-29}}</ref>
**[[Cold Medications]]<ref>[http://pediatrics.aappublications.org/cgi/content/full/108/3/e52 Official Journal of American Pediatrics - PEDIATRICS Vol. 108 No. 3 September 2001, p. e52 ]</ref> (ie. containing [[PPA]], or [[phenylpropanolamine]])
*prescription drugs, such as:
**[[barbiturate]]s<ref name=de_Paola_et_al_2004>{{cite journal | last = de Paola | first = Luciano | coauthors = Maria Joana Mäder, Francisco M.B. Germiniani, Patrícia Coral, Jorge A.A. Zavala, Djon J. Watzo, Jorge Kanegusuku, Carlos E.S. Silvado, and Lineu C. Werneck | year = 2004 | month = June | title = Bizarre behavior during intracarotid sodium amytal testing (Wada test): Are they predictable? | journal = Arquivos de Neuro-Psiquiatria | volume = 62 | issue = 2B | pages = 444-448 | doi = 10.1590/S0004-282X2004000300012 | id = {{PMID|15273841}} | url = http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X2004000300012&tlng=es&lng=en&nrm=iso | accessdate = 2006-10-15}}</ref><ref name=Sarrecchia_et_al_1998>{{cite journal | last = Sarrecchia | first = C. | coauthors = P. Sordillo, G. Conte, and G. Rocchi | year = 1998 | month = October-December | title = [Barbiturate withdrawal syndrome: a case associated with the abuse of a headache medication] | journal = Annali Italiani di Medicina Interna | volume = 13 | issue = 4 | pages = 237-239 | id = {{PMID|10349206}}}}</ref>
**[[benzodiazepine]]s<ref name=White_et_al_1982>{{cite journal | last = White | first = M. C. | coauthors = J. J. Silverman, and J. W. Harbison | year = 1982 | month = February | title = Psychosis associated with clonazepam therapy for blepharospasm | journal = Journal of Nervous and Mental Disease | volume = 170 | issue = 2 | pages = 117-9 | id = {{PMID|7057171}}}}</ref><ref name=Jaffe_et_al_1986>{{cite journal | last = Jaffe | first = R. | coauthors = E. Gibson | year = 1986 | month = June | title = Clonazepam withdrawal psychosis | journal = Journal of Clinical Psychopharmacology | volume = 6 | issue = 3 | pages = 193 | id = {{PMID|3711371}}}}</ref><ref name=Hallberg_et_al_1964>{{cite journal | last = Hallberg | first = R. J. | coauthors = K. Lessler and F. J. Kane | year = 1964 | month = August | title = KORSAKOFF-LIKE PSYCHOSIS ASSOCIATED WITH BENZODIAZEPINE OVERDOSAGE | journal = American Journal of Psychiatry | volume = 121 | issue = 2 | pages = 188-189 | doi = 10.1176/appi.ajp.121.2.188 | id = {{PMID|14194223}} | url = http://ajp.psychiatryonline.org/cgi/reprint/121/2/188 | format = PDF | accessdate = 2006-10-15}}</ref>
**Anticholinergic drugs
***[[atropine]]<ref name=Bergman_et_al_1980>{{cite journal | last = Bergman | first = K. R. | coauthors = C. Pearson, G. W. Waltz, and R. Evans III year = 1980 | month = December | title = Atropine-induced psychosis. An unusual complication of therapy with inhaled atropine sulfate | journal = Chest | volume = 78 | issue = 6 | pages = 891-893 | id = {{PMID|7449475}} | url = http://www.chestjournal.org/cgi/content/abstract/78/6/891 | format = Infotrieve | accessdate = 2006-10-15}}</ref><ref name=Varghese_et_al_1990>{{cite journal | last = Varghese | first = S. | coauthors = N. Vettath, K. Iyer, J. M. Puliyel, and M. M. Puliyel | year = 1990 | month = June | title = Ocular atropine induced psychosis--is there a direct access route to the brain? | journal = Journal of the Association of Physicians of India  | volume = 38 | issue = 6 | pages = 444-445 | id = {{PMID|2384469}}}}</ref>
***[[scopolamine]]<ref name=Barak_and_Weiner_2006>{{cite journal | last = Barak | first = Segev | coauthors = Ina Weiner | date = [[September 13]], [[2006]] | title = Scopolamine Induces Disruption of Latent Inhibition Which is Prevented by Antipsychotic Drugs and an Acetylcholinesterase Inhibitor | journal = Neuropsychopharmacology | doi = 10.1038/sj.npp.1301208 | id = {{PMID|16971898}} | url = http://www.nature.com/npp/journal/vaop/ncurrent/full/1301208a.html | accessdate = 2006-10-15}}</ref>
***[[Jimson weed]]<ref name=Kurzbaum>{{cite journal | last = Kurzbaum | first = Alberto | coauthors = Claudia Simsolo, Ludmilla Kvasha and Arnon Blum | year = 2001 | month = July | title = Toxic Delirium due to Datura Stramonium | journal = Israel Medical Association Journal | volume = 3 | issue = 7 | pages = 538-539 | id = {{PMID|11791426}} | url = http://www.ima.org.il/imaj/ar01jul-16.pdf | format = PDF | accessdate = 2006-10-17}}</ref>
**[[antidepressants]]
**[[antiepileptics]]<ref>Ettinger AB. "Psychotropic effects of antiepileptic drugs". Neurology. 2006 Dec 12;67(11):1916-25.</ref>
**medications (usually cold medications) that contain [[phenylpropanolamine]] or [[PPA]] <ref>http://ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&list_uids=3060884 Psychiatric side effects attributed to phenylpropanolamine, ''Pharmacopsychiatry'' 1988 Jul; 21(4):171-81</ref>
 
*"street" drugs, such as:
**[[cocaine]]<ref name=>{{cite journal | last = Brady | first = K. T. | coauthors = R. B. Lydiard, R. Malcolm, and J. C. Ballenger | year = 1991 | month = December | title = Cocaine-induced psychosis. | journal = Journal of Clinical Psychiatry | volume = 52 | issue = 12 | pages = 509-512 | id = {{PMID|1752853}}}}</ref>
**[[amphetamine]]s
**[[hallucinogens]] such as
***[[LSD]]
***[[psilocybin]]
***[[mescaline]]
***[[MDMA]] (ecstasy)
***[[Phencyclidine|PCP]]<ref name=psychotic_PCP_rats>{{cite journal | last = Reynolds | first = Lindsay M. | coauthors = Susan M. Cochran, Brian J. Morris, Judith A. Pratt and Gavin P. Reynolds | date = [[March 1]], [[2005]] | title = Chronic phencyclidine administration induces schizophrenia-like changes in ''N''-acetylaspartate and ''N''-acetylaspartylglutamate in rat brain | journal = Schizophrenia Research | volume = 73 | issue = 2-3 | pages = 147-152 | doi = 10.1016/j.schres.2004.02.003 | id = {{PMID|15653257}} | url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=pubmed_AbstractPlus&cmd=Retrieve&db=pubmed&list_uids=15653257&dopt=ExternalLink | accessdate = 2006-09-29}}</ref>
 
Intoxication with drugs that have general depressant effects on the [[central nervous system]] (especially alcohol and barbiturates) tend not to cause psychosis during use, and can actually decrease or lessen the impact of symptoms in some people. However, ''withdrawal'' from barbiturates and alcohol can be particularly dangerous, leading to psychosis or delirium and other, potentially lethal, withdrawal effects.
 
Some studies indicate that [[cannabis (drug)|cannabis]] use may lower the threshold for psychosis, and thus help to trigger full-blown psychosis in some people.<ref name = Deg> {{cite journal| last = Degenhardt | first = L | authorlink = | coauthors = Smith J, Steel R, Johnstone CE, Frith CD | title = Editorial: The link between cannabis use and psychosis: furthering the debate.  | journal = Psychological Medicine| volume = 33| issue = | pages = 3-6| publisher = PubMed| date = 2003| url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12537030| doi = | id = PMID 12537030 | accessdate = 2006-08-19 }}</ref> Early studies have been criticized for failing to consider other drugs (such as [[LSD]]) that the participants may have used before or during the study, as well as other factors such as pre-existing ("comorbid") mental illness. However, more recent studies with better controls have still found a small increase in risk for psychosis in cannabis users {{Fact|date=April 2007}}. 
 
It is not clear whether this is a causal link, and it is possible that cannabis use only increases the chance of psychosis in people already predisposed to it; or that people with developing psychosis use cannabis to provide temporary relief of their mental discomfort. The fact that cannabis use has increased over the past few decades, whereas the rate of psychosis has not, suggests that a direct causal link is unlikely for all users.<ref> {{cite paper| author = Degenhardt L, Hall W, Lynskey M  | title = Comorbidity between cannabis use and psychosis: Modelling some possible relationships.| version = Technical Report No. 121. | publisher = Sydney: National Drug and Alcohol Research Centre.| date = 2001 | url = http://ndarc.med.unsw.edu.au/NDARCWeb.nsf/resources/TR_18/$file/TR.121.PDF| format = [[PDF]]| accessdate = 2006-08-19 }}</ref>
 
==Signs and symptoms==
===Hallucinations===
Hallucinations are defined as sensory perception in the absence of external stimuli. They are different from [[illusion]]s, or [[perceptual distortions]], which are the misperception of external stimuli.<ref>{{cite web |url=http://www.etymonline.com/index.php?search=hallucinate&searchmode=none |title=hallucinate |accessmonthday=October 15 |accessyear=2006 |last=Harper |first= Douglas |year=2001 |month=November |work=Online Etymology Dictionary }}</ref> Hallucinations may occur in any of the five senses and take on almost any form, which may include simple sensations (such as lights, colors, tastes, and smells) to more meaningful experiences such as seeing and interacting with fully formed animals and people, hearing voices and complex tactile sensations.
 
Auditory hallucinations, particularly the experience of hearing voices, are a common and often prominent feature of psychosis. Hallucinated voices may talk about, or to the person, and may involve several speakers with distinct personas. Auditory hallucinations tend to be particularly distressing when they are derogatory, commanding or preoccupying. However, the experience of hearing voices need not always be a negative one. Research has shown that the majority of people who hear voices are not in need of psychiatric help.<ref> {{cite web| last = Honig| first = A | authorlink = | coauthors = Romme MA, Ensink BJ, Escher SD, Pennings MH, deVries MW | title = Auditory hallucinations: a comparison between patients and nonpatients | work = Journal of Nervous and Mental Disease | publisher = | date = 1998 | url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=9788642 | format = | doi = | accessdate = 2006-08-19 }}</ref> The [[Hearing Voices Movement]] has subsequently been created to support voice hearers, regardless of whether they are considered to have a mental illness or not.
 
=== Delusions and paranoia ===
Psychosis may involve [[delusion]]al or [[paranoia|paranoid]] beliefs. [[Karl Jaspers]] classified psychotic delusions into ''primary'' and ''secondary'' types.  Primary delusions are defined as arising out of the blue and not being comprehensible in terms of normal mental processes, whereas secondary delusions may be understood as being influenced by the person's background or current situation (e.g., ethnic or sexual discrimination, religious beliefs, superstitious belief).<ref name=Jaspers>{{cite book | last = Jaspers | first = Karl | authorlink = Karl Jaspers | others = Translated by J. Hoenig & M.W. Hamilton from German | title = Allgemeine Psychopathologie (General Psychopathology) | origyear = 1963 | edition = Reprint edition | date = 1997-11-27 | publisher = Johns Hopkins University Press | location = Baltimore, Maryland | language = English | id = ISBN 0-8018-5775-9}}</ref>
 
=== Thought disorder ===
[[Formal thought disorder]] describes an underlying disturbance to conscious thought and is classified largely by its effects on speech and writing.  Affected persons may show pressure of speech (speaking incessantly and quickly), derailment or flight of ideas (switching topic mid-sentence or inappropriately), [[thought blocking]], and rhyming or punning.
 
=== Lack of insight ===
One important and puzzling feature of psychosis is usually an accompanying lack of insight into the unusual, strange, or bizarre nature of the person's experience or behaviour.<ref name=Carpenter_et_al_1973>{{cite journal | last = Carpenter | first = William T., Jr., John S. Strauss, and John J. Bartko | date = [[December 21]], [[1973]] | title = Flexible system for the diagnosis of schizophrenia: Report from the WHO international pilot study of schizophrenia | journal = Science | volume = 182 | issue = 4118 | pages = 1275-1278 | doi = 10.1126/science.182.4118.1275 | id = {{PMID|4752222}} | url = http://www.sciencemag.org/cgi/content/abstract/182/4118/1275 | format = [http://www.sciencemag.org/cgi/reprint/182/4118/1275 PDF] | accessdate = 2006-10-21}}</ref> Even in the case of an acute psychosis, people may be completely unaware that their vivid hallucinations and impossible delusions are in any way unrealistic. This is not an absolute, however; insight can vary between individuals and throughout the duration of the psychotic episode.
 
It was previously believed that lack of insight was related to general cognitive dysfunction<ref name=Lysaker_et_al_1994>{{cite journal | last = Lysaker | first = Paul H. | coauthors = Morris D. Bell | year = 1994 | month = November | title = Insight and cognitive impairment in schizophrenia. Performance on repeated administrations of the Wisconsin Card Sorting Test | journal = Journal of Nervous and Mental Disease | volume = 182 | issue = 11 | pages = 656-660 | id = {{PMID|7964675}}}}</ref> or to avoidant coping style.<ref name=Lysaker_et_al_2003>{{cite journal | last = Lysaker | first = Paul H. | coauthors = Gary J. Bryson, Rebecca S. Lancaster, Jovier D. Evans and Morris D. Bell | date = [[January 1]], [[2003]] | title = Insight in schizophrenia: associations with executive function and coping style | journal = Schizophrenia Research | volume = 59 | issue = 1 | pages = 41-47 | doi = 10.1016/S0920-9964(01)00383-8 | id = {{PMID|12413641}} | url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=pubmed_Abstract&cmd=Retrieve&db=pubmed&list_uids=12413641&dopt=ExternalLink | accessdate = 2006-10-22}}</ref> Later studies have found no statistical relationship between insight and cognitive function, either in groups of people who only have schizophrenia,<ref name=>{{cite journal | last = Freudenreich | first = Oliver | coauthors = Thilo Deckersbach and Donald C. Goff | year = 2004 | month = July | title = Insight into current symptoms of schizophrenia. Association with frontal cortical function and affect | journal = Acta Psychiatrica Scandinavica | volume = 110 | issue = 1 | pages = 14-20 | doi = 10.1111/j.1600-0447.2004.00319.x | id = {{PMID|15180775}} | url = http://www.blackwell-synergy.com/doi/full/10.1111/j.1600-0447.2004.00319.x | accessdate = 2006-10-22}}</ref> or in groups of psychotic people from various diagnostic categories.<ref name=Cuesta_et_al_2006>{{cite journal | last = Cuesta | first = Manuel J. | coauthors = Victor Peralta, Amalia Zarzuela, and Maria Zandio | date = [[May 31]], [[2006]] | title = Insight dimensions and cognitive function in psychosis: a longitudinal study | journal = BMC Psychiatry | volume = 6 | pages = 26-35 | doi = 10.1186/1471-244X-6-26 | id = {{PMID|16737523}} | url = http://www.biomedcentral.com/1471-244X/6/26 | accessdate = 2006-10-22}}</ref>
 
In some cases, particularly with auditory and visual hallucinations, the person experiencing the hallucinations has good insight, which may make the psychotic experience even more terrifying because the person realizes that he or she should not be hearing voices, but is.
 
== Pathophysiology ==
[[Neuroimaging|Brain imaging]] studies of psychosis, investigating both changes in brain structure and changes in brain function of people undergoing psychotic episodes, have shown mixed results.
 
The first brain image of an individual with psychosis was completed as far back as 1935 using a technique called [[pneumoencephalography]]<ref> {{cite journal| last = Moore| first = M T | authorlink = | coauthors = Nathan D, Elliot AR, Laubach C| title = Encephalographic studies in mental disease. | journal = American Journal of Psychiatry| volume = 92| issue = 1| pages = 43-67| publisher = | date = 1935| url = | doi = | id = | accessdate = }}</ref> (a painful and now obsolete procedure where [[cerebrospinal fluid]] is drained from around the brain and replaced with air to allow the structure of the brain to show up more clearly on an [[X-ray]] picture).
 
More recently, a 2003 study investigating structural changes in the brains of people with psychosis showed there was significant [[grey matter]] reduction in the [[Cerebral cortex|cortex]] of people before and after they became psychotic.<ref> {{cite journal| last = Pantelis | first = C | authorlink = | coauthors = Velakoulis D, McGorry PD, Wood SJ, Suckling J, Phillips, LJ, Yung AR, Bullmore ET, Brewer W, Soulsby B, Desmond, P, McGuire PK | title = Neuroanatomical abnormalities before and after onset of psychosis: a cross-sectional and longitudinal MRI comparison. | journal = Lancet| volume = 25| issue = 361 (9354)| pages = 281-8| publisher = PubMed| date = 2003| url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgicmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12559861| doi = | id = PMID 12559861| accessdate = 2006-08-19 }}</ref> Findings such as these have led to debate about whether psychosis is itself [[neurotoxic]] and whether potentially damaging changes to the brain are related to the length of psychotic episode. Recent research has suggested that this is not the case<ref> {{cite journal| last = Ho | first = BC | authorlink = | coauthors = Alicata D, Ward J, Moser DJ, O'Leary DS, Arndt S, Andreasen NC| title = Untreated initial psychosis: relation to cognitive deficits and brain morphology in first-episode schizophrenia.| journal = American Journal of Psychiatry| volume = 160| issue = 1| pages = 142-148| publisher = PubMed| date = 2003| url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgicmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12559861| doi = | id = PMID 12505813| accessdate = 2006-08-19 }}</ref> although further investigation is still ongoing.
 
Functional brain scans have revealed that the areas of the brain that react to sensory perceptions are active during psychosis. For example, a [[Positron emission tomography|PET]] or [[Functional MRI|fMRI]] scan of a person who claims to be hearing voices may show activation in the auditory cortex, or parts of the brain involved in the perception and understanding of speech.<ref> Copolov DL, Seal ML, Maruff P, Ulusoy R, Wong MT, Tochon-Danguy HJ, Egan GF. (2003) Cortical activation associated with the experience of auditory hallucinations and perception of human speech in schizophrenia: a PET correlation study. ''Psychiatry Res'', 122 (3), 139-52. PMID 12694889. </ref>
 
On the other hand, there is not a clear enough psychological definition of [[belief]] to make a comparison between different people particularly valid. Brain imaging studies on delusions have typically relied on correlations of brain activation patterns with the presence of delusional beliefs.<ref>Bell, V., Halligan, P.W. & Ellis, H.D. (2006) A Cognitive Neuroscience of Belief. In P.W. Halligan & M. Aylward (eds) ''The Power of Belief''. Oxford: Oxford University Press.</ref>
 
One clear finding is that persons with a tendency to have psychotic experiences seem to show increased activation in the right hemisphere of the brain.<ref> {{cite journal| last = Lohr | first = JB | authorlink = | coauthors = Caligiuri MP| title = Lateralized hemispheric dysfunction in the major psychotic disorders: historical perspectives and findings from a study of motor asymmetry in older patients.| journal = Schizophrophrenia Research| volume = 30| issue = 27 (2-3)| pages = 191-8| publisher = PubMed| date = 1997| url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9416648| doi = | id = PMID 9416648| accessdate = 2006-08-19 }}</ref> This increased level of right hemisphere activation has also been found in healthy people who have high levels of [[paranormal]] beliefs<ref> {{cite journal| last = Pizaagalli | first = D | authorlink = | coauthors = Lehmann D, Gianotti L, Koenig T, Tanaka H, Wackermann J, Brugger P. | title = Brain electric correlates of strong belief in paranormal phenomena: intracerebral EEG source and regional Omega complexity analyses.| journal = Psychiatry Research| volume = 100| issue = 3| pages = 139-154| publisher = PubMed| date = 2000| url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11120441| doi = | id = PMID 11120441| accessdate = 2006-08-19 }}</ref> and in people who report [[mystical]] experiences.<ref> {{cite journal| last = Makarec | first = K | authorlink = | coauthors = Persinger, MA | title = Temporal lobe signs: electroencephalographic validity and enhanced scores in special populations.| journal = Perceptual and Motor Skills| volume = 60| issue = 3| pages = 831-842| publisher = PubMed| date = 1985| url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3927256| doi = | id = PMID 3927256| accessdate = 2006-08-19 }}</ref> It also seems to be the case that people who are more creative are also more likely to show a similar pattern of brain activation.<ref>{{cite journal| last = Weinstein | first = S | authorlink = | coauthors = Graves RE | title = Are creativity and schizotypy products of a right hemisphere bias? | journal = Brain and Cognition| volume = 49| issue = 1| pages = 138-151| publisher = PubMed| date = 2002| url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=pubmed_Abstract&cmd=Retrieve&db=pubmed&list_uids=12027399&dopt=ExternalLink| doi = | id = PMID 12027399 | accessdate = 2006-08-19 }}</ref> Some researchers have been quick to point out that this in no way suggests that paranormal, mystical or creative experiences are in any way ''by themselves'' a symptom of mental illness, as it is still not clear what makes some such experiences beneficial whilst others lead to the impairment or distress of diagnosable mental pathology. However, people who have profoundly different experiences of reality or hold unusual views or opinions have traditionally held a complex role in society, with some being viewed as [[Crank (person)|kook]]s, whilst others are lauded as [[prophet]]s or visionaries.
 
Psychosis has been traditionally linked to the [[neurotransmitter]] [[dopamine]]. In particular, the [[dopamine hypothesis of psychosis]] has been influential and states that psychosis results from an overactivity of dopamine function in the brain, particularly in the [[mesolimbic pathway]]. The two major sources of evidence given to support this theory are that dopamine-blocking drugs (i.e. [[antipsychotic]]s) tend to reduce the intensity of psychotic symptoms, and that drugs which boost dopamine activity (such as amphetamine and [[cocaine]]) can trigger psychosis in some people (see [[amphetamine psychosis]]).<ref> Kapur S, Mizrahi R, Li M. (2005) From dopamine to salience to psychosis - linking biology, pharmacology and phenomenology of psychosis. ''Schizophr Res'', 79 (1), 59-68. PMID 16005191</ref> However, increasing evidence in recent times has pointed to a possible dysfunction of the excitory neurotransmitter [[glutamate]], in particular, with the activity of the [[NMDA receptor]]. This theory is reinforced by the fact that [[dissociative]] [[NMDA receptor antagonists]] such as [[ketamine]], [[PCP]] and [[dextromethorphan]]/[[detrorphan]] (at large overdoses) induce a psychotic state more readily than dopinergic stimulants, even at "normal" recreational doses. The symptoms of dissociative [[intoxication]] are also considered to mirror the symptoms of schizophrenia more closely, including [[negative psychotic symptoms]] than amphetamine psychosis. Dissociative induced psychosis happens on a more reliable and predictable basis than amphetamine psychosis, which usually only occurs in cases of overdose, prolonged use or with [[sleep deprivation]], which can independantly produce psychosis. New antipsychotic drugs which act on glutamate and it's receptors are currently undergoing clinical trials.
(See [[glutamate hypothesis of psychosis]])
 
The connection between dopamine and psychosis is generally believed to be complex.  While antipsychotic drugs immediately block dopamine receptors, they usually take a week or two to reduce the symptoms of psychosis. Moreover, newer and equally effective antipsychotic drugs actually block slightly less dopamine in the brain than older drugs whilst also affecting [[serotonin]] function, suggesting the 'dopamine hypothesis' may be oversimplified.<ref> Jones, H. M., & Pilowsky, L. S. (2002) Dopamine and antipsychotic drug action revisited. ''British Journal of Psychiatry'', 181, 271-275. PMID 12356650 </ref> Soyka and colleagues found no evidence of dopaminergic dysfunction in people with alcohol-induced psychosis<ref name=>{{cite journal | last = Soyka | first = Michael | coauthors = Thomas Zetzsche, Stefan Dresel, and Klaus Tatsch | year = 2000 | month = May | title = FDG-PET and IBZM-SPECT Suggest Reduced Thalamic Activity but No Dopaminergic Dysfunction in Chronic Alcohol Hallucinosis | journal = Journal of  Neuropsychiatry & Clinical Neurosciences | volume = 12 | issue = 2 | pages = 287-288 | id = {{PMID|11001615}} | url = http://neuro.psychiatryonline.org/cgi/content/full/12/2/287 | accessdate = 2006-10-15}}</ref> and  Zoldan et al. reported moderately successful use of [[ondansetron]], a 5-HT<sub>3</sub> receptor antagonist, in the treatment of [[levodopa]] psychosis in [[Parkinson's disease]] patients.<ref name=Zoldan_et_al_1995>{{cite journal | last = Zoldan | first = J. | coauthors = G. Friedberg, M. Livneh, and E. Melamed. | year = 1995 | month = July | title = Psychosis in advanced Parkinson's disease: treatment with ondansetron, a 5-HT3 receptor antagonist | journal = Neurology | volume = 45 | issue = 7 | pages = 1305-1308 | id = {{PMID|7617188}}}}</ref>
 
Psychiatrist [[David Healy (psychiatrist)|David Healy]] has criticised pharmaceutical companies for promoting simplified biological theories of mental illness that seem to imply the primacy of pharmaceutical treatments while ignoring social and developmental factors which are known to be important influences in the aetiology of psychosis.<ref>{{cite book| last = Healy| first = David| authorlink = David Healy (psychiatrist)|David Healy | coauthors = | title = The Creation of Psychopharmacology| publisher = Harvard University Press| date = 2002 | location = Cambridge | url = | doi = | id = ISBN 0-674-00619-4 }}</ref>
 
Some theories regard many psychotic symptoms to be a problem with the perception of ownership of internally generated thoughts and experiences.<ref> {{cite journal| last = Blakemore | first = SJ | authorlink = | coauthors = Smith J, Steel R, Johnstone CE, Frith CD | title = The perception of self-produced sensory stimuli in patients with auditory hallucinations and passivity experiences: evidence for a breakdown in self-monitoring. | journal = Psychological Medicine| volume = 30| issue = 5| pages = 1131-9| publisher = PubMed| date = 2000| url = http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12027049| doi = | id = PMID 12027049 | accessdate = 2006-08-19 }}</ref> For example, the experience of hearing voices may arise from internally generated speech that is mislabeled by the psychotic person as coming from an external source.


==Treatment==
==Treatment==
The treatment of psychosis often depends on what associated diagnosis (such as schizophrenia or bipolar disorder) is thought to be present. However, the [[first line treatment]] for psychotic symptoms is usually a neuroleptic (also termed '[[antipsychotic]]') medication, and in some cases [[hospitalisation]]. There is growing evidence that [[cognitive behavior therapy]]<ref> {{cite journal| last = Birchwood | first = M | authorlink = | coauthors = Trower P | title = The future of cognitive-behavioural therapy for psychosis: not a quasi-neuroleptic. | journal = British Journal of Psychiatry | volume = 188 | issue = | pages = 108-108 | publisher = | date = 2006 | url = | doi = | id = PMID 16449695 | accessdate = 2006-08-19 }}</ref> and [[family therapy]]<ref> {{cite journal| last = Haddock | first = G | authorlink = | coauthors = Lewis S | title = Psychological interventions in early psychosis. | journal = Schizophrenia Bulletin | volume = 31 | issue = 3 | pages = 697-704 | publisher = | date = 2005 | url = | doi = | id = PMID 16006594 | accessdate = 2006-08-19 }}</ref> can be effective in managing psychotic symptoms.  When other treatments for psychosis are ineffective, [[electroconvulsive therapy]] (ECT) (aka shock treatment) is sometimes utilized to relieve the underlying symptoms of psychosis, such as depression or schizophrenia. There is also increasing research suggesting that [[Animal-Assisted Therapy]] can contribute to the improvement in general well-being of people with schizophrenia.<ref name=Nathans-Barel_et_al_2005>{{cite journal | last = Nathans-Barel | first = I. | coauthors = P. Feldman, B. Berger, I. Modai and H. Silver | year = 2005 | title = Animal-assisted therapy ameliorates anhedonia in schizophrenia patients | journal = Psychotherapy and Psychosomatics | volume = 74 | issue = 1 | pages = 31-35}}</ref>
[[Psychosis medical therapy|Medical Therapy]] | [[Psychosis primary prevention|Primary Prevention]] | [[Psychosis secondary prevention|Secondary Prevention]] | [[Psychosis cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Psychosis future or investigational therapies|Future or Investigational Therapies]]
 
==Further reading==
*Sims, A. (2002) ''Symptoms in the mind: An introduction to descriptive psychopathology (3rd edition)''. Edinburgh: Elsevier Science Ltd. ISBN 0-7020-2627-1
 
===Personal accounts===
*Dick, P.K. (1981) ''VALIS''. London: Gollancz. [Semi-autobiographical] ISBN 0-679-73446-5
*Hinshaw, S.P. (2002) ''The Years of Silence are Past: My Father's Life with Bipolar Disorder''. Cambridge: Cambridge University Press.
*Jamison, K.R. (1995) ''An Unquiet Mind: A Memoir of Moods and Madness''. London: Picador.<br> ISBN 0-679-76330-9
*Schreber, D.P. (2000) ''Memoirs of My Nervous Illness''. New York: New York Review of Books. ISBN 0-940322-20-X
*McLean, R (2003) ''Recovered Not Cured: A Journey Through Schizophrenia''. Allen & Unwin. Australia. ISBN 1-86508-974-5
*The Eden Express by Mark Vonnegut
*James Tilly Matthews
*Saks, Elyn R. (2007) ''The Center Cannot Hold -- My Journey Through Madness''. New York: Hyperion. ISBN 978-1-4013-0138-5
 
==Links==
* [[Apparitional experience]]
* [[Delusional disorder]]
* [[Monothematic delusions]]
* [[Jerusalem syndrome]]
* [[Clinical Lycanthropy]]
* [[Soteria]]
* [[Hallucinations in the sane]]
 
==References==
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<references/>
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==External links==
* [http://www.mind.org.uk/Information/Booklets/Understanding/Understanding+Psychotic+Experiences.htm Understanding psychotic experiences] from mental health charity [[Mind (charity)|Mind]]
 
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==Case Studies==
[[Psychosis case study one|Case #1]]
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Latest revision as of 23:52, 29 July 2020


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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vindhya BellamKonda, M.B.B.S [2] Somal Khan, MD Kiran Singh, M.D. [3]

Synonyms and keywords: Acute and transient psychotic disorders; acute polymorphic psychotic disorder; anxiety bliss psychosis; anxiety elation psychosis; anxiety happiness psychosis; atypical psychosis; bipolar psychosis; brief psychotic disorder; brief reactive psychosis; cycloid psychosis; good prognosis schizophrenia; hysterical psychosis; mood disturbances; mood disorders; psychogenic psychosis; reactive schizophrenia; schizophrenia; schizophrenia spectrum; schizophreniform disorder; schizoaffective disorder; stress psychosis; substance induced psychosis; thought disturbances; transient psychosis

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Psychosis from other Disorders

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications, and Prognosis

Diagnosis

History and Symptoms | Physical Examination | Laboratory Findings | Electroencephalogram | Other Diagnostic Studies

Treatment

Medical Therapy | Primary Prevention | Secondary Prevention | Cost-Effectiveness of Therapy | Future or Investigational Therapies

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Case #1 Template:WH Template:WS