Effects of lithium on vigilance, psychomotoric performance and mood.

It can be expected that investigations on the effect of lithium on the "normal" human mind may elucidate the influence of lithium on experience and behaviour during the "free interval" of manic-depressive patients. In a placebo-controlled double-blind trial 24 normal healthy volunteers were given lithium sulphate (24--36 mval/die) or placebo over a period of two weeks. The subjects were tested after one and two weeks drug intake using the following tests: quantitative pharmaco-EEG, psychological performance, and mood scales. In comparison to placebo lithium shows decreased flicker fusion threshold, and mood change towards depression (Bf-S). In the resting EEG a decrease of relative slow alpha (7.5--9.0 cps)--and an increase of relative fast beta (20.0--30.0, and 30.0--48.0 cps)--power was observed. The results suggest that lithium leads to decreased vigilance and reduced spontaneous activity.