Editing Psychosis (section)

== Diagnosis ==
To make a diagnosis of a mental illness in someone with psychosis [[diagnosis of exclusion|other potential causes must be excluded]].<ref name="Ol2012">{{cite web| vauthors = Freudenreich O |title=Differential Diagnosis of Psychotic Symptoms: Medical "Mimics"|url=http://www.psychiatrictimes.com/forensic-psychiatry/differential-diagnosis-psychotic-symptoms-medical-%E2%80%9Cmimics%E2%80%9D|website=Psychiatric Times|publisher=UBM Medica|date=3 December 2012|access-date=16 March 2017|archive-date=4 June 2013|archive-url=https://web.archive.org/web/20130604094749/http://www.psychiatrictimes.com/forensic-psychiatry/differential-diagnosis-psychotic-symptoms-medical-%E2%80%9Cmimics%E2%80%9D|url-status=live}}</ref> An initial assessment includes a comprehensive history and physical examination by a health care provider. Tests may be done to exclude substance use, medication, toxins, surgical complications, or other medical illnesses. A person with psychosis is referred to as psychotic.

[[Delirium]] should be ruled out, which can be distinguished by visual hallucinations, acute onset and fluctuating level of consciousness, indicating other underlying factors, including medical illnesses.<ref name="Med_News">{{cite news| vauthors = Nordqvist C |title=What Is Schizoaffective Disorder? What Causes Schizoaffective Disorder?|url=http://www.medicalnewstoday.com/articles/190678.php|access-date=March 16, 2017|newspaper=Medical News Today|date=August 8, 2016|archive-date=June 5, 2010|archive-url=https://web.archive.org/web/20100605080349/http://www.medicalnewstoday.com/articles/190678.php|url-status=live}}</ref> Excluding medical illnesses associated with psychosis is performed by using blood tests to measure:
* [[thyroid-stimulating hormone]] to exclude [[hypothyroidism|hypo-]] or [[hyperthyroidism]],
* [[Vitamin B12|vitamin B<sub>12</sub>]] serum and urinary [[Methylmalonic acid|MMA]] to role out [[pernicious anemia]] or [[Vitamin B12 deficiency|vitamin B<sub>12</sub> deficiency]],
* [[Blood tests#Blood chemistry tests|basic electrolytes]] and [[serum calcium]] to rule out a metabolic disturbance,
* [[full blood count]] including [[erythrocyte sedimentation rate|ESR]] to rule out a systemic infection or chronic disease, and
* [[serology]] to exclude [[syphilis]] or [[HIV]] infection.

Other investigations include:
* [[EEG]] to exclude [[epilepsy]], and an
* [[MRI]] or [[CT scan]] of the head to exclude brain lesions.

Because psychosis may be precipitated or exacerbated by common classes of medications, medication-induced psychosis should be [[diagnosis of exclusion|ruled out]], particularly for first-episode psychosis. Both substance- and medication-induced psychosis can be [[diagnosis of exclusion|excluded]] to a high level of certainty, using toxicology screening.

Because some [[dietary supplement]]s may also induce psychosis or mania, but cannot be ruled out with laboratory tests, a psychotic individual's family, partner, or friends should be asked whether the patient is currently taking any dietary supplements.<ref>{{cite journal | title = Final rule declaring dietary supplements containing ephedrine alkaloids adulterated because they present an unreasonable risk. Final rule | journal = Federal Register | volume = 69 | issue = 28 | pages = 6787–6854 | date = February 2004 | pmid = 14968803 | url = http://www.federalregister.gov/a/04-2912/p-276 | access-date = 2014-09-29 | url-status = live | archive-url = https://web.archive.org/web/20210829020131/https://www.federalregister.gov/documents/2004/02/11/04-2912/final-rule-declaring-dietary-supplements-containing-ephedrine-alkaloids-adulterated-because-they | archive-date = 2021-08-29 | author-link1 = Food and Drug Administration | last1 = Food Drug Administration | first1 = HHS }} ({{Federal Register|69|6814}} and {{Federal Register|69|6818}})</ref>

Common mistakes made when diagnosing people who are psychotic include:<ref name="Ol2012" />
* Not properly excluding [[delirium]],
* Not appreciating medical abnormalities (e.g., vital signs),
* Not obtaining a medical history and family history,
* Indiscriminate screening without an organizing framework,
* Missing a toxic psychosis by not screening for substances ''and'' medications,
* Not asking their family or others about dietary supplements,
* Premature diagnostic closure, and
* Not revisiting or questioning the initial diagnostic impression of primary psychiatric disorder.

Only after relevant and known causes of psychosis are excluded, a mental health clinician may make a psychiatric [[differential diagnosis]] using a person's family history, incorporating information from the person with psychosis, and information from family, friends, or significant others.

Types of psychosis in psychiatric disorders may be established by formal rating scales. The [[Brief Psychiatric Rating Scale]] (BPRS)<ref>{{cite journal | vauthors = Overall JE, Gorham DR | title = The Brief Psychiatric Rating Scale. | journal = Psychol. Rep. | date = 1962 | volume = 10 | issue = 3 | pages = 799–812 | doi = 10.2466/pr0.1962.10.3.799 | s2cid = 143531021 }}</ref> assesses the level of 18 symptom constructs of psychosis such as [[hostility]], [[Suspicion (emotion)|suspicion]], [[hallucination]], and [[grandiosity]]. It is based on the clinician's interview with the patient and observations of the patient's behavior over the previous 2–3 days. The patient's family can also answer questions on the behavior report. During the initial assessment and the follow-up, both positive and negative symptoms of psychosis can be assessed using the 30 item Positive and Negative Symptom Scale ([[PANSS]]).<ref>{{cite journal | vauthors = Kay SR, Fiszbein A, Opler LA | title = The positive and negative syndrome scale (PANSS) for schizophrenia | journal = Schizophrenia Bulletin | volume = 13 | issue = 2 | pages = 261–276 | year = 1987 | pmid = 3616518 | doi = 10.1093/schbul/13.2.261 | doi-access = free }}</ref>

The [[DSM-5]] characterizes disorders as psychotic or on the schizophrenia spectrum if they involve hallucinations, delusions, disorganized thinking, grossly disorganized motor behavior, or negative symptoms.<ref name="DSM">{{cite book | author = American Psychiatric Association |title=Diagnostic and statistical manual of mental disorders : DSM-5.|date=2013|publisher=American Psychiatric Association|location=Washington, D.C.|isbn=978-0-89042-554-1|page=[https://archive.org/details/diagnosticstatis0005unse/page/125 125]|edition=5th|url=https://archive.org/details/diagnosticstatis0005unse/page/125}}</ref> The DSM-5 does not include psychosis as a definition in the glossary, although it defines "psychotic features", as well as "psychoticism" with respect to personality disorder. The [[ICD-10]] has no specific definition of psychosis.<ref name="Gaebel">{{cite journal | vauthors = Gaebel W, Zielasek J | title = Focus on psychosis | journal = Dialogues in Clinical Neuroscience | volume = 17 | issue = 1 | pages = 9–18 | date = March 2015 | pmid = 25987859 | pmc = 4421906 | doi = 10.31887/DCNS.2015.17.1/wgaebel }}</ref>

The PSQ (Psychosis Screening Questionnaire) is the most common tool in detecting psychotic symptoms and it includes five root questions that assess the presence of PLE (mania, thought insertion, paranoia, strange experiences and perceptual disturbances)<ref>{{Cite journal |last1=Thungana |first1=Yanga A. |last2=Zingela |first2=Zukiswa |last3=Wyk |first3=Stefan J. Van |last4=Kim |first4=Hannah H. |last5=Ametaj |first5=Amantia |last6=Stevenson |first6=Anne |last7=Stroud |first7=Rocky E. |last8=Stein |first8=Dan J. |last9=Gelaye |first9=Bizu |date=2023 |title=Psychosis screening questionnaire: Exploring its factor structure among South African adults |url=https://sajp.org.za/index.php/sajp/article/view/2051 |journal=South African Journal of Psychiatry |language=en |volume=29 |pages=7 |doi=10.4102/sajpsychiatry.v29i0.2051 |pmc=10696556 |pmid=38059200}}</ref> The different tools used to assess symptom severity include the Revised Behavior and Symptom Identification Scale (BASIS-R), a 24-item self-report instrument with six scales: psychosis, depression/functioning, interpersonal problems, alcohol/drug use, self-harm, and emotional lability. The Symptom Checklist-90-Revised (SCL-90-R), a 90-item self assessment tool that measures psychoticism and paranoid ideation in addition to seven other symptom scales. Finally, the Brief Symptom Inventory (BSI), a 53-item self-administered scale developed from the SCL-90-R. The BSI has good psychometric properties and is an acceptable brief alternative to the SCL-90-R.<ref>U.S. Department of Veterans Affairs. (2024, February 15). ''VA.gov | Veterans affairs''. MIRECC / CoE Home. <nowiki>https://www.mirecc.va.gov/visn22/Assessment_Tools_for_Measuring_Outcomes_in_Psychosis.asp#top</nowiki></ref> These seem to be the most accurate tools at the moment, but a research in 2007 that focused on quantifying self-reports of auditory verbal hallucinations (AVH) in persons with psychosis, suggest that The Hamilton Program for Schizophrenia Voices Questionnaire (HPSVQ) is also potentially a reliable and useful measure for specifically quantifying AVHs in relation to psychosis.<ref>Van Lieshout, R. J., & Goldberg, J. O. (2007). Quantifying self-reports of auditory verbal hallucinations in persons with psychosis. ''Canadian Journal of Behavioural Science/Revue Canadienne Des Sciences Du Comportement, 39''(1), 73–77. <nowiki>https://doi.org/10.1037/cjbs2007006</nowiki></ref>

[[Factor analysis]] of symptoms generally regarded as psychosis frequently yields a five factor solution, albeit five factors that are distinct from the five domains defined by the DSM-5 to encompass [[psychotic]] or schizophrenia spectrum disorders. The five factors are frequently labeled as hallucinations, delusions, disorganization, excitement, and emotional distress.<ref name="Gaebel" /> The DSM-5 emphasizes a [[psychotic spectrum]], wherein the low end is characterized by schizoid personality disorder, and the high end is characterized by schizophrenia.<ref name="Continuum" />

Gouzoulis-Mayfrank et al. said that the pleasant or emotionally positive experiences that are common in psychosis, particularly in the early stages, are more easily overlooked in clinical practice than the negative experiences.<ref name="ReferenceA">Friesen P. Psychosis and psychedelics: Historical entanglements and contemporary contrasts.&nbsp;Transcultural Psychiatry. 2022;59(5):592-609. https://doi.org/10.1177/13634615221129116</ref> Nev Jones and Mona Shattel wrote that there is less curiosity towards the complications, or towards the richness of the good things as well as the bad things.<ref name="ReferenceA"/>