Measures of Depressive Mood at Monthly Intervals

¹ Director of Clinical Research, Crichton Royal Hospital, Dumfries
² Senior Registrar, Crichton Royal Hospital, Dumfries

This report arose from a pilot trial to establish the methodology for a double-blind controlled trial of secondary prevention in recurrent depressive disorders. At the out-patient clinic, at monthly intervals, eight patients and two psychiatrists independently scored severity of depression using a Visual Analogue Scale. The Beck Depression Inventory was then completed.

Findings

(i) The scores on the VAS of the two independent assessors were not significantly different.

(ii) The patients' ratings on the VAS were significantly higher than those obtained from the two psychiatrists, while the BDI scores, expressed as a percentage of the maximum possible, were lower for the group as a whole.

(iii) The three sets of scores correlated highly and positively when taken overall. For six of the eight subjects the psychiatrists' and the patients' VAS scores correlated significantly. For five of the eight patients, one or other of the VAS scores correlated significantly with the BDI.

For some purposes measurement of change in depressive mood during the course of an illness is more important than absolute level; there were no significant differences between the three methods as measures of direction and amount of mood change at monthly intervals.

As an overall measure the Beck Depression Inventory, which is relatively time-consuming, had few clear advantages over the Visual Analogue Scale, which only took a moment or so to complete. The quickest single method of optimal sensitivity was the Visual Analogue Scale scored by the psychiatrist; the Scale, whether rated by psychiatrist or the patient or both, offers the clinician a reliable record of mood during the course of a depressive illness, with minimal expenditure of effort and time.

Although the Visual Analogue Scale has been used by nurses (Zealley and Aitken, 1969), its value for psychiatrists' ratings of depressive mood has not previously been reported.