Editing Schizophrenia (section)

===Criteria===
Schizophrenia is diagnosed based on criteria in either the ''[[Diagnostic and Statistical Manual of Mental Disorders]]'' (DSM) published by the [[American Psychiatric Association]] or the [[ICD|International Statistical Classification of Diseases and Related Health Problems]] (ICD) published by the [[World Health Organization]] (WHO). These criteria use the self-reported experiences of the person and reported abnormalities in behavior, followed by a [[psychiatric assessment]]. The [[mental status examination]] is an important part of the assessment.<ref>{{cite journal | vauthors = Soltan M, Girguis J | title = How to approach the mental state examination | url = https://www.bmj.com/content/357/sbmj.j1821 | journal = BMJ | volume = 357 | page = j1821 | access-date = 9 January 2020 | doi = 10.1136/sbmj.j1821 | pmid = 31055448 | date = 8 May 2017| s2cid = 145820368 }}</ref> An established tool for assessing the severity of positive and negative symptoms is the [[Positive and Negative Syndrome Scale]] (PANSS).<ref>{{cite journal | vauthors = Lindenmayer JP | title = Are Shorter Versions of the Positive and Negative Syndrome Scale (PANSS) Doable? A Critical Review. | journal = Innovations in Clinical Neuroscience | date = 1 December 2017 | volume = 14 | issue = 11–12 |pages=73–76 | pmid = 29410940| pmc = 5788254 }}</ref> This has been seen to have shortcomings relating to negative symptoms, and other scales – the ''Clinical Assessment Interview for Negative Symptoms'' (CAINS), and the ''Brief Negative Symptoms Scale'' (BNSS) have been introduced.<ref name=Marder2014/> The [[DSM-5]], published in 2013, gives a ''Scale to Assess the Severity of Symptom Dimensions'' outlining eight dimensions of symptoms.<ref name=Biedermann2016/>

DSM-5 states that to be diagnosed with schizophrenia, two diagnostic criteria have to be met over the period of one month, with a significant impact on social or occupational functioning for at least six months. One of the symptoms needs to be either delusions, hallucinations, or disorganized speech. A second symptom could be one of the negative symptoms, or severely disorganized or [[catatonia|catatonic behaviour]].<ref name=DSM5/> A different diagnosis of [[schizophreniform disorder]] can be made before the six months needed for the diagnosis of schizophrenia.<ref name=DSM5/>

In Australia, the guideline for diagnosis is for six months or more with symptoms severe enough to affect ordinary functioning.<ref>{{cite web |title=Diagnosis of schizophrenia |url=https://www.healthdirect.gov.au/diagnosis-of-schizophrenia |publisher= Australian Department of Health |access-date=28 January 2020 |date=10 January 2019}}</ref> In the UK diagnosis is based on having the symptoms for most of the time for one month, with symptoms that significantly affect the ability to work, study, or carry on ordinary daily living, and with other similar conditions ruled out.<ref>{{cite web |title=Schizophrenia – Diagnosis |url=https://www.nhs.uk/conditions/schizophrenia/diagnosis/ |publisher= UK [[National Health Service]] |access-date=28 January 2020 |date=23 October 2017}}</ref>

The ICD criteria are typically used in European countries; the DSM criteria are used predominantly in the United States and Canada, and are prevailing in research studies. In practice, agreement between the two systems is high.<ref>{{cite journal | vauthors = Jakobsen KD, Frederiksen JN, Hansen T, Jansson LB, Parnas J, Werge T | title = Reliability of clinical ICD-10 schizophrenia diagnoses | journal = Nordic Journal of Psychiatry | volume = 59 | issue = 3 | pages = 209–212 | year = 2005 | pmid = 16195122 | doi = 10.1080/08039480510027698 | s2cid = 24590483 }}</ref> The current proposal for the [[ICD-11]] criteria for schizophrenia recommends adding self-disorder as a symptom.<ref name=Heinz2016/>

A major unresolved difference between the two diagnostic systems is that of the requirement in DSM of an impaired functional outcome. WHO for ICD argues that not all people with schizophrenia have functional deficits and so these are not specific for the diagnosis.<ref name=Biedermann2016/>