The expression of the 'pre-menstrual syndrome' in measures of mood and sustained attention.

Twenty-eight women performed two demanding sustained attention tasks in the premenstrual and intermenstrual phases of the menstrual cycle. Mood was assessed before and after performance. No effects of phase were found on perceptual sensitivity and response criterion, but response time on the less demanding of the two tasks was slower in the premenstrual phase. There were no effects of phase on pre-task mood, but following performance, premenstrual women were lower in energy and in pleasantness of mood. Moods varied with phase irrespective of usage of the contraceptive pill, but effects on response time were stronger in non-pill users. Performance data suggest that speed of visual discrimination varies with the cycle, but this finding is of little practical significance. The mood data suggest that the affective correlates of the cycle vary with situational stress, and, in the workplace, it may be desirable to reduce stress and workload during the premenstrual phase.