The research described in this thesis aimed to investigate emotional and sexual variations experienced by women during the Menstrual Cycle including the phenomenon of "Premenstrual Tension ", and relate such changes to the sex steroids, Oestradiol, Progesterone and Androgens.
An extensive and critical review of the literature indicates that confusing and conflicting evidence in the area of hormone - behaviour relationships in women relates primarily to methodological issues. In this study particular attention was paid to distinguishing women with different experiences of cyclical mood changes and to the measurement of hormones and behaviour.
The study involved a group of 55 women with normal regular menstrual cycles. One third of these were recruited from a gynaecology clinic after complaining of severe Premenstrual Tension, the "Clinic" Group. The rest were volunteers recruited from various sources. Half of these women also experienced cyclical changes, the "Report PMT" Group. The others, the "No PMT" Group, noticed no cyclical variations in wellbeing.
The women completed daily ratings of their moods, physical health, sexual feelings and sexual activities over one menstrual cycle. Frequent blood samples were taken and levels of Oestradiol, Progesterone, Testosterone and Androstenedione were measured using radioimmunoassay. The hormone measures were used firstly)to distinguish normal ovulatory cycles from those which were endocrinologically unusual or anovulatory; secondly, oestradiol and progesterone levels were used to divide each cycle into six ix
phases in order to relate behaviour to hormonally defined stages of the cycle; and thirdly to examine correlations between levels of hormones and ratings of moods and sexuality.
1. Moods and Premenstrual Tension: The emotional and physical changes observed were consistent with initial the women's /reports. The "Clinic" group showed significant changes in their wellbeing across the cycle phases. These women's moods and energy began to decline after ovulation, reaching the lowest point in the premenstrual phase. The volunteers who reported premenstrual tension showed a similar but less pronounced pattern, although their wellbeing declined later, in the mid luteal phase. As expected, there were no significant cyclical changes in moods in the women with no PMT : however, mild breast tenderness before menstruation was common.
PMT may be a more marked version of common and less problem - matical cyclical changes. A longer and more pronounced deterioration of moods and energy in the luteal phase with a decline in sexual interest characterised the clinical extreme of PMT.
The relationship between PMT and hormones was examined by endocrinological comparison of the three groups. There were no significant differences in levels of oestradiol, progesterone, or the ratio of oestradiol to progesterone. There were slight differences in the pattern of hormonal changes in the luteal phase: - in the "Clinic" group progesterone levels started to fall earlier and there was a greater drop in levels of oestradiol and progesterone in comparison with the other women.
Correlations between hormones and behaviour in the "Clinic" group indicated that low progesterone and changing levels in the luteal phase were related to lack of wellbeing, low energy and x
physical distress. There was little relationship between oestradiol and moods although physical distress was related to low levels in the premenstrual phase. There were some correlations between androgens and energy.
The "Clinic" group differed from the other women in that they frequently had histories of adverse reactions to oral contraceptive agents and many of these women had experienced problems during and after pregnancy. This suggests that sensitivity to hormones may be an important factor in the aetiology of Premenstrual Tension.
The relationship between androgens and Premenstrual Tension was also examined and indicated some complex links. Women in the "Clinic" group appeared to have low androgen levels but further analysis revealed that this was related to their marital status and occupation rather than premenstrual tension. This leads to interesting speculations regarding the interrelationships betweeñ hormones, cyclical mood changes and social and situational factors.
2. Sexuality, Hormones and the Menstrual Cycle: There was no evidence of any mid -cycle increase in any aspects of these women's sexuality. The main pattern was related to menstruation with a peak of sexual interest, feelings and woman - initiated activities after menstruation, in the mid follicular phase. Partner- initiated activities peaked after ovulation.
The pattern of sexual interest and activities was influenced by general wellbeing and energy. Women with a pronounced deterioration in wellbeing before menstruation were less sexually interested or active at this time but statistical analysis indicated that this was predominately related to general mood changes, particularly lack of energy.
Correlations between hormones and sexuality revealed some interesting and complex links. Oestradiol was not obviously related to sexual interest or activities but there were suggestions that Progesterone had an inhibitory influence. Correlations between Testosterone and sexuality were significant but negative. However for those women who masturbated, frequency of sexual activities was positively correlated with testosterone levels.
The implications of these hormone -behaviour correlations are discussed in a framework of interactions between social, psychological and hormonal factors contributing to behavioural changes during the menstrual cycle.