Editing Schizophrenia (section)

===Negative symptoms===
Negative symptoms are deficits of normal emotional responses, or of other thought processes. The five recognized domains of negative symptoms are: [[blunted affect]] – showing flat expressions (monotone) or little emotion; [[alogia]] – a poverty of speech; [[anhedonia]] – an inability to feel pleasure; [[asociality]] – the lack of desire to form relationships, and [[avolition]] – a lack of motivation and [[apathy]].<ref name=Adida2015>{{cite journal |vauthors=Adida M, Azorin JM, Belzeaux R, Fakra E |title=[Negative Symptoms: Clinical and Psychometric Aspects] |journal=L'Encephale |volume=41 |issue=6 Suppl 1 |pages=6S15–17 |date=December 2015 |pmid=26776385 |doi=10.1016/S0013-7006(16)30004-5}}</ref><ref>{{cite journal |vauthors=Mach C, Dollfus S |title=[Scale for Assessing Negative Symptoms in Schizophrenia: A Systematic Review] |journal=L'Encephale |volume=42 |issue=2 |pages=165–171 |date=April 2016 |pmid=26923997 |doi=10.1016/j.encep.2015.12.020}}</ref> Avolition and anhedonia are seen as motivational deficits resulting from impaired reward processing.<ref>{{cite book |vauthors=Waltz JA, Gold JM |title=Behavioral Neuroscience of Motivation |chapter=Motivational Deficits in Schizophrenia and the Representation of Expected Value | series = Current Topics in Behavioral Neurosciences|volume=27 |pages=375–410 |date=2016 |pmid=26370946 |doi=10.1007/7854_2015_385 |pmc=4792780 |isbn=978-3-319-26933-7 }}</ref><ref name=Husain2018>{{cite journal |vauthors=Husain M, Roiser JP |s2cid=49428707 |title=Neuroscience of apathy and anhedonia: a transdiagnostic approach. |journal=Nature Reviews. Neuroscience|volume=19 |issue=8 |pages=470–484 |date=August 2018 |pmid=29946157 |doi=10.1038/s41583-018-0029-9|url=https://ora.ox.ac.uk/objects/uuid:3e481f87-0ede-47dd-bdd8-2db78dfd3694 }}</ref> Reward is the main driver of motivation and this is mostly mediated by dopamine.<ref name=Husain2018/> It has been suggested that negative symptoms are multidimensional and they have been categorised into two subdomains of apathy or lack of motivation, and diminished expression.<ref name=Adida2015/><ref name=Galderisi2018>{{cite journal |vauthors=Galderisi S, Mucci A, Buchanan RW, Arango C |title=Negative symptoms of schizophrenia: new developments and unanswered research questions |journal=The Lancet. Psychiatry |volume=5 |issue=8 |pages=664–677 |date=August 2018 |pmid=29602739 |doi=10.1016/S2215-0366(18)30050-6 |s2cid=4483198 }}</ref> Apathy includes avolition, anhedonia, and social withdrawal; diminished expression includes blunt affect and alogia.<ref>{{cite journal |vauthors=Klaus F, Dorsaz O, Kaiser S |title=[Negative symptoms in schizophrenia – overview and practical implications] |journal=Revue médicale suisse |volume=14 |issue=619 |pages=1660–1664 |date=19 September 2018 |doi=10.53738/REVMED.2018.14.619.1660 |pmid=30230774|s2cid=246764656 }}</ref> Sometimes diminished expression is treated as both verbal and non-verbal.<ref>{{cite journal |vauthors=Batinic B |title=Cognitive Models of Positive and Negative Symptoms of Schizophrenia and Implications for Treatment. |journal=Psychiatria Danubina |volume=31 |issue=Suppl 2 |pages=181–184 |date=June 2019 |pmid=31158119}}</ref>

Apathy accounts for around 50% of the most often found negative symptoms and affects functional outcome and subsequent quality of life. Apathy is related to disrupted cognitive processing affecting memory and planning, including goal-directed behaviour.<ref>{{cite journal |vauthors=Bortolon C, Macgregor A, Capdevielle D, Raffard S |s2cid=13411386 |title=Apathy in schizophrenia: A review of neuropsychological and neuroanatomical studies. |journal=Neuropsychologia |volume=118 |issue=Pt B |pages=22–33 |date=September 2018 |pmid=28966139 |doi=10.1016/j.neuropsychologia.2017.09.033}}</ref> The two subdomains have suggested a need for separate treatment approaches.<ref name=Marder2014>{{cite journal |vauthors=Marder SR, Kirkpatrick B |s2cid=5172022 |title=Defining and measuring negative symptoms of schizophrenia in clinical trials |journal=European Neuropsychopharmacology|volume=24 |issue=5 |pages=737–743 |date=May 2014 |pmid=24275698 |doi=10.1016/j.euroneuro.2013.10.016}}</ref> A lack of distress is another noted negative symptom.<ref name=Tatsumi2020>{{cite journal |vauthors=Tatsumi K, Kirkpatrick B, Strauss GP, Opler M |s2cid=211141678 |title=The brief negative symptom scale in translation: A review of psychometric properties and beyond |journal=European Neuropsychopharmacology |date=April 2020 |volume=33 |pages=36–44 |doi=10.1016/j.euroneuro.2020.01.018 |pmid=32081498}}</ref> A distinction is often made between those negative symptoms that are inherent to schizophrenia, termed primary; and those that result from positive symptoms, from the side effects of antipsychotics, substance use disorder, and social deprivation, termed secondary negative symptoms.<ref>{{cite journal |vauthors=Klaus F, Kaiser S, Kirschner M |title=[Negative Symptoms in Schizophrenia – an Overview]. |journal=Therapeutische Umschau |volume=75 |issue=1 |pages=51–56 |date=June 2018 |pmid=29909762 |doi=10.1024/0040-5930/a000966|s2cid=196502392 }}</ref> Negative symptoms are less responsive to medication and the most difficult to treat.<ref name=Marder2014/> However, if properly assessed, secondary negative symptoms are amenable to treatment.<ref name=Galderisi2018/> There is some evidence that the negative symptoms of schizophrenia are amenable to psychostimulant medication, although such drugs have varying degrees of risk for causing positive psychotic symptoms.<ref name="sciencedirect.com">{{Cite journal |last1=Lindenmayer |first1=Jean-Pierre |last2=Nasrallah |first2=Henry |last3=Pucci |first3=Michael |last4=James |first4=Steven |last5=Citrome |first5=Leslie |date=2013-07-01 |title=A systematic review of psychostimulant treatment of negative symptoms of schizophrenia: Challenges and therapeutic opportunities |url=https://www.sciencedirect.com/science/article/abs/pii/S0920996413001655 |journal=Schizophrenia Research |volume=147 |issue=2 |pages=241–252 |doi=10.1016/j.schres.2013.03.019 |pmid=23619055 |issn=0920-9964}}</ref>

Scales for specifically assessing the presence of negative symptoms, and for measuring their severity, and their changes have been introduced since the earlier scales such as the [[Positive and Negative Syndrome Scale|PANNS]] that deals with all types of symptoms.<ref name=Marder2014/> These scales are the ''Clinical Assessment Interview for Negative Symptoms'' (CAINS), and the ''Brief Negative Symptom Scale'' (BNSS) also known as second-generation scales.<ref name=Marder2014/><ref name=Tatsumi2020/><ref>{{cite journal |vauthors=Wójciak P, Rybakowski J |title=Clinical picture, pathogenesis and psychometric assessment of negative symptoms of schizophrenia. |journal=Psychiatria Polska |volume=52 |issue=2 |pages=185–197 |date=30 April 2018 |pmid=29975360 |doi=10.12740/PP/70610|doi-access=free }}</ref> In 2020, ten years after its introduction, a cross-cultural study of the use of BNSS found valid and reliable [[psychometric]] evidence for its five-domain structure cross-culturally. The BNSS can assess both the presence and severity of negative symptoms of the five recognized domains and an additional item of reduced normal distress. It has been used to measure changes in negative symptoms in trials of psychosocial and pharmacological interventions.<ref name=Tatsumi2020/>