premenstrual tension The first ‘modern’ account of premenstrual tension (PMT) was published in a medical journal in 1931. Feelings of tension, self-deprecation, and even severe depression experienced by women in the 7–10 days preceding menstruation were accurately described. By the 1950s the list of symptoms reported by women in the premenstrual period had increased, and there was a growing realization that so-called ‘tension’ was just one aspect of the problems. In a paper published in 1953 the term ‘premenstrual syndrome’ was introduced to encompass the extending list of symptoms. The name eventually stuck, and the problem is now often referred to as PMS.

The symptoms of PMS include not only anxiety, irritability, and depression but also constipation, food cravings, sleep problems, tiredness, and a feeling of bloatedness, particularly in the abdominal area (due to water retention). These are just a few of the common complaints, and in fact it has been mooted that when all reported symptoms of PMS are added up the total can reach the unbelievable number of 160.

The incidence of PMS ranges from 5% to 95% according to different surveys which have been undertaken. For example, in a survey by Woman's Own magazine in 1993, nine out of ten women claimed to suffer from at least some of the symptoms. A study in the early 1980s by the World Health Organization reported that the incidence of premenstrual mood changes varied between 23% amongst Sudanese women to 73% amongst Muslim women in the then Yugoslavia. Thus one is left with the conclusion that women can and do suffer from PMS irrespective of culture and society. However, such a wide variation in the estimated incidence can either fuel the sceptics or suggest that not suffering from PMS is abnormal. In whatever way it is viewed, it is quite clear that many women do experience symptoms associated with their changing hormone levels during their menstrual cycle, and there is now growing awareness that symptoms described by patients as PMS are not always limited to the premenstrual period; they can extend into the menstrual period itself.

The causes of PMS remain unknown. It is generally believed that symptoms result from the waning hormone secretions from the ovaries as the corpus luteum begins to degenerate towards the end of the menstrual cycle. At this stage concentrations of progesterone and oestrogen in the circulating blood decline, and this is thought to precipitate the various symptoms. How the loss of these hormone secretions results in the physical, behavioural, and psychological symptoms ranging, for example, from abdominal bloating to food cravings and lethargy remains unknown, as does the question as to why some women should suffer from PMS while others do not. Theories have been proposed regarding the ratio of oestrogen to progesterone secretions or the absolute concentrations of these hormones, but these have not been consistently validated. More likely, the cause is an individual's response to her changing hormone secretions, which may be exacerbated by social and/or cultural influences.

There is no doubt that sex hormones can influence brain function. It has long been recognized that they can affect the neurotransmitters which transmit neural signals within the brain, and also the receptors on nerve cells which recognize these neurochemicals. Recent work has suggested that the specific receptors for serotonin (otherwise known as 5-hydroxy-tryptamine) are increased by oestrogens but decline when secretions of this hormone are reduced. A deficiency of this same neurotransmitter, or a loss of its receptors, has also been linked with food cravings. Thus it is possible that many of the symptoms of PMS may be caused by the loss of hormone secretions and a consequent reduction in some aspects of brain chemistry. It follows that treatment of symptoms with drugs that can increase serotonin activity, including vitamin B₆, can alleviate the symptoms of PMS.

However, the question still remains: can PMS be defined as a pathological condition or is it a ‘normal’ consequence of changing hormone secretions? In this respect it is interesting to note that women who are prone to suffer depression are more likely to suffer from PMS than those who do not. Perhaps one should consider that whether or not one suffers from PMS will very much depend on the ‘background’ of brain chemistry against which the hormones (or lack of them) are working.

Saffron Whitehead

Bibliography

Dalton, K. and and Holton, D. (1994). PMS. Harper Collins, London.

See also menstrual cycle.