Effects of lorazepam on emotional reactivity, performance, and vigilance in subjects with high or low anxiety.

This study examined the hypothesis that low doses of lorazepam modify emotional response. In accord with the results of prior studies that suggest a differential effect of benzodiazepines according to the subjects' anxiety level, the authors tested the effect of lorazepam (0.5 mg twice daily) on 2 groups of 32 subjects: those with high anxiety (HA) and those with low anxiety (LA). These groups were formed a priori on the basis of their scores on the Cattell Anxiety Scale and the Hamilton Rating Scale for Anxiety. The two groups were evaluated for psychomotor function and vigilance (visual analog scales [VAS], digit-symbol substitution test [DSST], and choice reaction time [CRT]), as well as emotional reactivity. Six emotions (fear, anger, disgust, sadness, joy, and neutral state) were induced by the presentation of six movie excerpts, and subjects' emotional responses were measured using the Differential Emotions Scale. The results suggest that at the doses studied, lorazepam led to an increase in negative emotions and a decrease in positive emotions, compared with placebo. This shift of emotional reactivity toward more negative emotions was slightly stronger with the HA than with the LA subjects. However, no reliable differences in the levels of performance and vigilance (CRT, DSST, and VAS) were observed as a function of either treatment or subject group. These findings suggest a possible relationship between benzodiazepine effects and subjects' anxiety level.