Clinical global impression

The clinical global impression (CGI) rating scales are measures of symptom severity, treatment response and the efficacy of treatments in treatment studies of patients with mental disorders.^[1] It is a brief 3-item observer-rated scale that can be used in clinical practice as well as in researches to track symptom changes. It was developed by Early Clinical Drug Evaluation Program (ECDEU) team of researchers for use in NIMH-led clinical trials that could provide clinical judgment based assessment for determining the severity of symptoms and the treatment progress. This was meant to assess the patient's functioning prior to and after initiating medication in trials which is an important part of study process. Its 3 items assess, 1) Severity of Illness (CGI-S), 2) Global Improvement (CGI-I), and 3) Efficacy Index (CGI-E, which is a measure of treatment effect and side effects specific to drugs that were administered). Many researchers,^[2]^[3] while recognizing the validity of the scale, consider it to be subjective as it requires the user of the scale to compare the subjects to typical patients in the clinician experience.

^ Guy, William (1976). "Clinical Global Impressions". ECDEU Assessment Manual for Psychopharmacology—Revised. Rockville, MD: U.S. Department of Health, Education, and Welfare; Public Health Service, Alcohol; Drug Abuse, and Mental Health Administration; National Institute of Mental Health; Psychopharmacology Research Branch; Division of Extramural Research Programs. pp. 218-222. OCLC 2344751. DHEW Publ No ADM 76–338 – via Internet Archive.
^ Samara, Myrto T.; Engel, Rolf R.; Millier, Aurelie; Kandenwein, Julia; Toumi, Mondher; Leucht, Stefan (November 2014). "Equipercentile linking of scales measuring functioning and symptoms: Examining the GAF, SOFAS, CGI-S, and PANSS". European Neuropsychopharmacology. 24 (11): 1767–1772. doi:10.1016/j.euroneuro.2014.08.009. PMID 25219937. S2CID 28853805.
^ Suzuki, Takefumi; Uchida, Hiroyuki; Sakurai, Hitoshi; Ishizuki, Tomomi; Tsunoda, Kenichi; Takeuchi, Hiroyoshi; Mimura, Masaru (June 2015). "Relationships between global assessment of functioning and other rating scales in clinical trials for schizophrenia". Psychiatry Research. 227 (2–3): 265–269. doi:10.1016/j.psychres.2015.02.024. PMID 25882098. S2CID 6298832.

[Guy1976-1] Guy, William (1976). "Clinical Global Impressions". ECDEU Assessment Manual for Psychopharmacology—Revised. Rockville, MD: U.S. Department of Health, Education, and Welfare; Public Health Service, Alcohol; Drug Abuse, and Mental Health Administration; National Institute of Mental Health; Psychopharmacology Research Branch; Division of Extramural Research Programs. pp. 218-222. OCLC 2344751. DHEW Publ No ADM 76–338 – via Internet Archive.

[2] Samara, Myrto T.; Engel, Rolf R.; Millier, Aurelie; Kandenwein, Julia; Toumi, Mondher; Leucht, Stefan (November 2014). "Equipercentile linking of scales measuring functioning and symptoms: Examining the GAF, SOFAS, CGI-S, and PANSS". European Neuropsychopharmacology. 24 (11): 1767–1772. doi:10.1016/j.euroneuro.2014.08.009. PMID 25219937. S2CID 28853805.

[3] Suzuki, Takefumi; Uchida, Hiroyuki; Sakurai, Hitoshi; Ishizuki, Tomomi; Tsunoda, Kenichi; Takeuchi, Hiroyoshi; Mimura, Masaru (June 2015). "Relationships between global assessment of functioning and other rating scales in clinical trials for schizophrenia". Psychiatry Research. 227 (2–3): 265–269. doi:10.1016/j.psychres.2015.02.024. PMID 25882098. S2CID 6298832.

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