Clinical Global Impression


The Clinical Global Impression rating scales are measures of symptom severity, treatment response and the efficacy of treatments in treatment studies of patients with mental disorders. Many researchers, 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.

Severity scale

The Clinical Global Impression – Severity scale is a 7-point scale that requires the clinician to rate the severity of the patient's illness at the time of assessment, relative to the clinician's past experience with patients who have the same diagnosis. Possible ratings are:

Improvement scale

The Clinical Global Impression – Improvement scale is a 7 point scale that requires the clinician to assess how much the patient's illness has improved or worsened relative to a baseline state at the beginning of the intervention. and rated as:

Efficacy index

The Clinical Global Impression – Efficacy Index is a 4×4 rating scale that assesses the therapeutic effect of treatment with psychiatric medication and associated side effects.