Relations between anxiety, psychophysiological variables and menstrual cycle in healthy women.

The present study was designed to explore whether changes occur in psychophysiological variables in healthy women not suffering from premenstrual tension. Variations in electroencephalogram frequencies, reaction time, somatosensory evoked potentials, and nerve conduction velocity were examined in a sample of 30 women, in relation to scores from the Hamilton Psychiatric Rating Scale for Depression and the State-Trait Anxiety Inventory. Trials and recordings were done weekly. EEG frequencies decreased before menstruation in all subjects. However, there were no significant changes for reaction time, nerve conduction velocity, HAMILTON nor State-Trait Anxiety scales associated with subperiods of the menstrual cycle. To explore the impact of anxiety, high and low anxiety groups were formed. The high anxiety group showed the highest scores in the A-Trait form, longer reaction time, enlarged latencies of the P100, but shorter nerve conduction velocity. Anxiety scores as well as reaction time increased during the premenstrual period only for the low anxiety group. The authors conclude that for some women premenstrual anxiety may be related to previous and continuous high levels of anxiety, which associated with some subtle neurological differences as compared with women who rated in low scores for anxiety.