Editing Schizophrenia (section)

===Cognitive symptoms===
{{See also |Visual processing abnormalities in schizophrenia}}
[[File:SchizophreniaBrain.jpg|thumb|Map of deficits in [[neural tissue]] throughout the human brain in a patient with schizophrenia. The most deficient areas are magenta, while the least deficient areas are blue.]]
An estimated 70% of those with schizophrenia have cognitive deficits, and these are most pronounced in early-onset and late-onset illness.<ref name=Murante2017/><ref name=Kar2016>{{cite journal |vauthors=Kar SK, Jain M |title=Current understandings about cognition and the neurobiological correlates in schizophrenia |journal=Journal of Neurosciences in Rural Practice |volume=7 |issue=3 |pages=412–418 |date=July 2016 |pmid=27365960 |doi=10.4103/0976-3147.176185 |pmc=4898111 |doi-access=free }}</ref> These are often evident long before the onset of illness in the [[Prodromal schizophrenia|prodromal stage]], and may be present in childhood or early adolescence.<ref name=Bozikas2011/><ref>{{cite journal | vauthors = Shah JN, Qureshi SU, Jawaid A, Schulz PE | s2cid = 10970088 | title = Is there evidence for late cognitive decline in chronic schizophrenia? | journal = The Psychiatric Quarterly | volume = 83 | issue = 2 | pages = 127–144 | date = June 2012 | pmid = 21863346 | doi = 10.1007/s11126-011-9189-8 }}</ref> They are a core feature but not considered to be core symptoms, as are positive and negative symptoms.<ref name=Biedermann2016>{{cite journal |vauthors = Biedermann F, Fleischhacker WW | title = Psychotic disorders in DSM-5 and ICD-11 | journal = CNS Spectrums | date = August 2016 | volume = 21 | issue = 4 | pages = 349–354 | doi = 10.1017/S1092852916000316 | pmid = 27418328| s2cid = 24728447 }}</ref><ref name=Vidailhet2013/> However, their presence and degree of dysfunction is taken as a better indicator of functionality than the presentation of core symptoms.<ref name=Bozikas2011>{{cite journal | vauthors = Bozikas VP, Andreou C | s2cid = 26135485 | title = Longitudinal studies of cognition in first episode psychosis: a systematic review of the literature | journal = The Australian and New Zealand Journal of Psychiatry | volume = 45 | issue = 2 | pages = 93–108 | date = February 2011 | pmid = 21320033 | doi = 10.3109/00048674.2010.541418 }}</ref> Cognitive deficits become worse at first episode psychosis but then return to baseline, and remain fairly stable over the course of the illness.<ref name=Hashimoto2019/><ref name=Green2019/>

The deficits in [[cognition]] are seen to drive the negative psychosocial outcome in schizophrenia, and are claimed{{By whom|date=March 2024}} to equate to a possible reduction in IQ from the norm of 100 to 70–85.<ref>{{cite journal | vauthors=Javitt DC, Sweet RA |title=Auditory dysfunction in schizophrenia: integrating clinical and basic features. |journal=Nature Reviews. Neuroscience|volume=16 |issue=9 |pages=535–550 |date=September 2015|pmid=26289573|doi=10.1038/nrn4002|pmc=4692466 }}</ref><ref name=Megreya2016>{{cite journal |vauthors=Megreya AM |s2cid=26125559 |title=Face perception in schizophrenia: a specific deficit |journal=Cognitive Neuropsychiatry |volume=21 |issue=1 |pages=60–72 |date=2016 |pmid=26816133|doi=10.1080/13546805.2015.1133407}}</ref>{{failed verification|date=January 2025}} Cognitive deficits may be of [[neurocognition]] (nonsocial) or of [[social cognition]].<ref name=Murante2017>{{cite journal |vauthors=Murante T, Cohen CI |title=Cognitive Functioning in Older Adults With Schizophrenia |journal=Focus (American Psychiatric Publishing) |volume=15 |issue=1 |pages=26–34 |date=January 2017 |pmid=31975837 |doi=10.1176/appi.focus.20160032|pmc=6519630 }}</ref> Neurocognition is the ability to receive and remember information, and includes verbal fluency, [[memory]], [[reason]]ing, [[problem solving]], [[Information processing (psychology)|speed of processing]], and [[auditory system|auditory]] and visual perception.<ref name=Green2019/> [[Verbal memory]] and attention are seen to be the most affected.<ref name=Megreya2016/><ref>{{cite journal |vauthors=Eack SM |title=Cognitive remediation: a new generation of psychosocial interventions for people with schizophrenia |journal=Social Work |volume=57 |issue=3 |pages=235–246 |date=July 2012 |pmid=23252315 |doi=10.1093/sw/sws008|pmc=3683242 }}</ref> Verbal memory impairment is associated with a decreased level of [[semantic processing]] (relating meaning to words).<ref>{{cite journal
|vauthors=Pomarol-Clotet E, Oh M, Laws KR, McKenna PJ | title=Semantic priming in schizophrenia: systematic review and meta-analysis |journal=The British Journal of Psychiatry |volume=192 |issue=2 | pages=92–97 |date=February 2008 |pmid=18245021 |doi=10.1192/bjp.bp.106.032102 | hdl=2299/2735 |doi-access=free |hdl-access=free }}</ref> Another memory impairment is that of [[episodic memory]].<ref>{{cite journal | vauthors = Goldberg TE, Keefe RS, Goldman RS, Robinson DG, Harvey PD | title = Circumstances under which practice does not make perfect: a review of the practice effect literature in schizophrenia and its relevance to clinical treatment studies | journal = Neuropsychopharmacology | volume = 35 | issue = 5 | pages = 1053–1062 | date = April 2010 | pmid = 20090669 | pmc = 3055399 | doi = 10.1038/npp.2009.211 | df = dmy-all }}</ref> An impairment in visual perception that is consistently found in schizophrenia is that of [[visual backward masking]].<ref name=Green2019/> [[Visual processing]] impairments include an inability to perceive complex [[visual illusion]]s.<ref>{{cite journal |vauthors=King DJ, Hodgekins J, Chouinard PA, Chouinard VA, Sperandio I |title=A review of abnormalities in the perception of visual illusions in schizophrenia. |journal=Psychonomic Bulletin and Review |volume=24 |issue=3 |pages=734–751 |date=June 2017 |pmid=27730532 |doi=10.3758/s13423-016-1168-5 |pmc = 5486866}}</ref> Social cognition is concerned with the mental operations needed to interpret, and understand the self and others in the social world.<ref name=Green2019>{{cite journal |vauthors=Green MF, Horan WP, Lee J |title=Nonsocial and social cognition in schizophrenia: current evidence and future directions |journal=World Psychiatry|volume=18 |issue=2 |pages=146–161 |date=June 2019 |pmid=31059632 |doi=10.1002/wps.20624|pmc=6502429 }}</ref><ref name=Murante2017/> This is also an associated impairment, and [[Face perception#Schizophrenia|facial emotion perception]] is often found to be difficult.<ref>{{cite journal | vauthors = Kohler CG, Walker JB, Martin EA, Healey KM, Moberg PJ | title = Facial emotion perception in schizophrenia: a meta-analytic review | journal = Schizophrenia Bulletin | volume = 36 | issue = 5 | pages = 1009–1019 | date = September 2010 | pmid = 19329561 | pmc = 2930336 | doi = 10.1093/schbul/sbn192 | df = dmy-all }}</ref><ref>{{cite journal | vauthors = Le Gall E, Iakimova G | title = [Social cognition in schizophrenia and autism spectrum disorder: Points of convergence and functional differences] | journal = L'Encéphale | volume = 44 | issue = 6 | pages = 523–537 | date = December 2018 | pmid = 30122298 | doi = 10.1016/j.encep.2018.03.004 | s2cid = 150099236 }}</ref> Facial perception is critical for ordinary social interaction.<ref>{{cite journal | vauthors = Grill-Spector K, Weiner KS, Kay K, Gomez J | title = The Functional Neuroanatomy of Human Face Perception | journal = Annual Review of Vision Science | volume = 3 | pages = 167–196 | date = September 2017 | pmid = 28715955 | pmc = 6345578 | doi = 10.1146/annurev-vision-102016-061214 }}</ref> Cognitive impairments do not usually respond to antipsychotics, and there are a number of [[#Psychosocial interventions|interventions]] that are used to try to improve them; [[cognitive remediation therapy]] is of particular help.<ref name=Vidailhet2013/>

[[Neurological soft signs]] of clumsiness and loss of fine motor movement are often found in schizophrenia, which may resolve with effective treatment of FEP.<ref name=Ferri2019/><ref>{{cite journal |vauthors=Fountoulakis KN, Panagiotidis P, Kimiskidis V, Nimatoudis I, Gonda X |s2cid=56476015 |title=Neurological soft signs in familial and sporadic schizophrenia |journal=Psychiatry Research |volume=272 |pages=222–229 |date=February 2019 |pmid=30590276 |doi=10.1016/j.psychres.2018.12.105 }}</ref>