The Clinical Global Impression Scale – Psychosis version, or CGI psychosis, is a simple tool to measure illness severity in psychosis.

It has been designed to evaluate five different groups of symptoms and the overall severity of the disorder.

The five groups of symptoms are :

Positive symptoms - such as delusions and hallucinations.

Negative symptoms - such as reduced expressed emotion and speech.

Depressive symptoms - such as sustained low mood and hopelessness.

Cognitive symptoms - such as impaired attention and difficulty in abstract thinking.

And excitement symptoms – such as mania and irritability.

All items of the CGI Psychosis are rated on a 7 point scale. Ranging from Normal not ill at all, to minimally, mildly, moderately, markedly, severely, and among the most severely ill.

The CGI psychosis should be completed after conducting a clinical interview.

Ratings should be based on the interview as well as all other available information, such as family or carer reports and clinical notes.

The ratings should be based on the past week.

Each of the 5 groups of symptoms, should be rated according to their severity.

Considering how often the symptom occurred and how distressing it was for the patient, as well as any issues it caused over the past week.

For example, consider whether the patient’s symptoms affected their functioning at work, school, home, or in social situations.

The final rating should evaluate the overall severity of the illness.

Make a global judgement taking into account the severity of all of the patient’s symptoms and any issues they’ve caused over the past week.