Psychiatric conditions often involve multiple symptoms, functional changes, and evolving treatment responses that can be difficult to summarize concisely. The Clinical Global Impression (CGI) is a brief clinician rated scale used to capture overall illness severity, global improvement, and the balance between therapeutic benefit and tolerability. It is widely used in both clinical practice and research because it distills broad clinical impressions into clear, standardized ratings.
This resource page explains how the CGI works, the purpose of each of its components, and how clinicians can incorporate the scale into routine assessment. By structuring observations into simple and consistent ratings, the CGI helps clinicians evaluate change over time and communicate progress across visits or treatment settings.
A downloadable PDF of the Clinical Global Impression is available for clinicians using the download resource button above.
Understanding How the CGI Works
The CGI contains three clinician rated sections that each serve a specific purpose. The Severity of Illness rating evaluates how ill the patient appears at the time of assessment, using a seven point scale that ranges from not at all ill to among the most extremely ill patients. The Global Improvement rating compares the patient’s current presentation to their baseline, indicating whether their overall condition has improved, stayed the same, or worsened. The Efficacy Index summarizes the relationship between symptom improvement and side effect burden, offering a concise way to consider whether the overall effect of treatment is favorable.
“Global rating scales help clinicians capture the overall impression of a patient’s status and change over time, adding perspective to symptom specific measures.”
— National Institute of Mental Health
This perspective reflects the role of the CGI as a complement to disorder specific assessments. While the CGI does not measure individual symptoms in detail, it provides a meaningful overview that supports treatment evaluation and shared decision making. Clinicians can review the full scale and rating anchors in the downloadable resource using the download resource button above.
Frequently Asked Questions
Clinicians consider mood, anxiety, thought content, behavior, functioning, and overall clinical presentation when forming a global impression. These observations may be informed by interviews, collateral information, and changes in daily functioning. Integrating these factors supports a comprehensive overview of the patient’s status.
The CGI allows clinicians to compare current presentation with prior visits, offering a straightforward way to evaluate whether treatment is resulting in meaningful improvement. Tracking these changes over time helps guide medication adjustments, behavioral interventions, and monitoring strategies.
Yes, the CGI is designed to be flexible and can be used across mood disorders, anxiety disorders, psychotic disorders, and other psychiatric conditions. Its broad focus makes it useful in settings where clinicians evaluate general illness severity and overall clinical change.
The Efficacy Index reflects both therapeutic benefit and side effect burden. It helps clinicians determine whether the overall effect of treatment is positive or whether changes may be needed. This balanced view supports safe and individualized medication management.
The CGI is often used alongside symptom rating scales, functional assessments, and patient reported outcomes. Combining global and detailed measures helps clinicians develop a more complete understanding of treatment response and overall well being.
Conclusion
The Clinical Global Impression is a concise and versatile tool that helps clinicians summarize illness severity, treatment response, and the overall balance of benefit and tolerability. Its simple structure allows for quick integration into clinical encounters while maintaining meaningful clinical relevance. Using the CGI helps clinicians clearly articulate changes in status and make informed decisions about next steps in care.
Incorporating the CGI into routine evaluation supports consistent monitoring, collaborative care, and clear communication among treatment providers. The downloadable resource provides the complete scale and rating anchors using the download resource button above. The Clinical Global Impression is an important part of comprehensive psychiatric assessment and ongoing treatment evaluation.
The Clinical Global Impression supports clear tracking of overall clinical change and helps guide thoughtful treatment planning.