CAFFEINE USE - IS THERE A NET BENEFIT FOR MOOD AND PSYCHOMOTOR PERFORMANCE

We agree with the conclusions of a recent article in this journal [Jam es, Neuropsychobiology 1994;30:124-125] that studies on the psychoacti ve effects of caffeine need to take into account the possibility that the results obtained might represent merely the reversal of deleteriou s effects of caffeine deprivation rather than an actual net benefit du e to caffeine use. However, in a review of recent studies we find no u nequivocal evidence of impaired psychomotor performance associated wit h caffeine withdrawal. This is in contrast to a clear deterioration of mood which occurs even after overnight caffeine deprivation. We concl uded that current evidence points to true performance-enhancing effect s of caffeine, although the extent of these and the conditions under w hich caffeine is most effective have yet to be fully determined. At th e same time, the existence of significant detrimental effects of caffe ine deprivation on psychomotor performance has not been ruled out.