Clinical Global Impression scale

Clinical Global Impressions (CGI)

Main reference: Guy W: ECDEU Assessment Manual for Psychopharmacology - Revised (DHEW Publ No ADM 76-338). Rockville, MD, U.S. Department of Health, Education, and Welfare, Public Health Service, Alcohol, Drug Abuse, and Mental Health Administration, NIMH Psychopharmacology Research Branch, Division of Extramural Research Programs, 1976, pp 218-222.

Type: Clinician-rated scale.

Main indications: Designed to assess global severity of illness and change in the clinical condition over time.

Rating performed by: Trained rater.

Time period covered by scale: Current clinical state.

Time required to complete rating: 1-2 minutes after a clinical interview.

Remarks: Standardized assessment tool. Consists of 3 global subscales:

• Severity of illness
• Global improvement
• Efficacy index

Used widely in psychopharmacology trials.