Comparative validity of two measures of psychomotor function in patients with severe depression.

Psychomotor function is a key construct in depressed patients and two measures have been developed for systematic rating. Parker and colleagues utilise an observer-rated scale (CORE) while the scale (DRRS) developed by Widlöcher assesses motor and ideational aspects. Association between the scales and their relative capacity to predict ECT response were investigated in a sample of 81 depressed patients. Both predicted ECT response. While the CORE scale rates a wider variety of phenomena (including non-interactiveness and agitation) and does not rely on the subject's capacity to report aspects of their cognitive function, the study supports the predictive and comparitive validity of both scales.