A Visual Analogue Scale technique to measure global vigor and affect.

This article describes an easily administered Visual Analogue Scale (VAS) technique that can be used to detect changes in mood and subjective activation. The method yields two summary measures: Global Vigor (GV) and Global Affect (GA), each ranging in value from 0 to 100. The instrument was administered about six times per day in 38 healthy control and 6 depressed patients participating in temporal isolation studies. This yielded a total of 5,734 control subject sessions and 575 patient sessions. For both groups, frequency distributions of GV and GA were shown to be approximately Gaussian, and evidence was obtained suggesting that the instrument was being completed properly. On average, depressives were about 0.6 standard deviations lower than controls in GV and about 1.5 standard deviations lower in GA, confirming the validity of the scales. Measures of GV in controls were shown to be sensitive to both jet lag and diurnal variation, thus confirming the reliability and validity of GV in these situations. In two studies involving more than 50 days of voluntary seclusion, measures of GA were found to show an almost monotonic decline, tracking the decline in mood and confirming the reliability and validity of GA in that situation.