The Present State Examination Change Rating Scale.

The development and use of a new psychiatric symptom change scale based on the Present State Examination (PSE)--the PSE Change Rating Scale--is described. The advantages of the PSE are retained (the extensive glossary, the diagnostic facility and the standardised interview technique) while improving its sensitivity to change and decreasing its administration time. The scale has been designed to prevent feedback of results and 'halo' effects: it has proved highly reliable in use across raters with different backgrounds and experience. The scale has been used to monitor drug effects on clinical state across a variety of diagnoses and examples of its use are given.