Women fought long and hard to have pre-menstrual syndrome recognised and medicalised. Now, believes Aminatta Forna, we need to fight equally hard to dispel the myths surrounding it. Yet researchers into the condition find themselves in a political minefield: more and more evidence points to psychological causes, yet to say so is to arouse the fury of those who feel they are being told their suffering is 'all in the mind'

NOTHING winds women up more than PMS. Not the condition, so much as the subject. Twenty years after PMS struggled for a name and for recognition, pre-menstrual syndrome has now become medicalised, legalised, socialised and politicised. The industry in remedies for PMS is now worth pounds 87 million, in the courts women have successfully used PMS as a murder defence and, in recent weeks, to claim unfair dismissal against an employer; one routinely hears women refer to their own monthly battles with PMS. Yet despite all this validation, scientists struggle to quantify and to describe PMS, whose causes and cures remain elusive. Discussions around PMS are still intensely emotive and able to provoke fury, hostility and an extraordinary strength of feeling.

The most recent research on PMS coming from Australia purports to demonstrate that the causes of PMS are psychological, and it has been met with a firestorm of protest from furious women "sufferers". Some years ago, I interviewed researchers conducting studies on PMS. Several of the people I spoke to confessed their own private doubts about how far this "syndrome" could be claimed to have any kind of biological basis at all, but refused to be quoted directly because of the public response they were bound to provoke. At least one interviewee for this article confessed to receiving hate mail related to their work on PMS. PMS, it seems, has become a political touchstone for an enormous number of sensibilities.

It used to be the case that anyone who challenged the notion of PMS was accused of being old-fashioned and unenlightened (especially if they were male), but current critiques of PMS, like the Australian study, are being provided by women. They are seeking to place PMS in a social and cultural context, which takes account of other influences, such as gender roles, mental health and personal circumstances (in much the same way as eating disorders have been understood) rather than categorising it as a purely medical condition.

Elizabeth Hardie's research, conducted at Swinburne University in Australia, set out to examine the notion that PMS was a problem at work. They compared groups of women who said they had PMS with women who did not, and also with men. All the groups demonstrated mood swings at work, but only the women who claimed PMS ascribed the problems to their periods. However, the researchers also found that the same group of women complained of an assortment of problems such as high stress, ill health and impaired work, irrespective of whether their periods were approaching. The findings confirmed an earlier British study. "In contrast to the suggestion that the problem of PMS be acknowledged," said Elizabeth Hardie, "it is time this myth was dispelled." But it's precisely remarks like this which provoke outrage among women who say they have PMS and conclude that they are being told their problem doesn't exist.

The Australian findings are the latest in a growing body of research which indicates that the causes of PMS may not be biological. A massive World Health Organisation study incorporating interviews with 5,000 women in 10 countries found PMS to exist exclusively in Western, industrialised nations. In all other respects the views and knowledgeability about menstruation of the participants, wherever they came from, were remarkably consistent. When Professor John Richardson of Brunel University made similar claims, to the effect that PMS was determined as much by psychological and cultural factors as biological ones, he found himself profiled in the Mail on Sunday under the headline: "The Man Who Says PMS Doesn't Exist". People, he says, "have great difficulty getting round the idea that something can be psychological or even socio-cultural and yet also perfectly genuine."

Jane Usher, one of the directors of the Women's Health Research Institute at University College London, has called PMS the "heir of hysteria". The label of "hysterical" was applied to Victorian women in remarkably similar ways to that in which PMS is used as a description of convenience now. Hysteria was thought to be caused by the roving womb, literally the womb moving around the body. Many women manifested the kinds of symptoms associated with hysteria - fainting fits and wasting illnesses, for instance. But historians now believe these were more likely responses to the constrained and restricted lives women were forced to endure. "Linking women's frustration and anger to reproductive functions" has been going on for centuries, says Ussher. And figures of a placebo effect of between 20 and 80 per cent evidenced in trials for remedies for PMS are grist to her argument that PMS could be a psychological condition.

In recognition of new theories, some professional bodies are even dispensing with the name pre-menstrual syndrome, on the basis that what is being dealt with is hardly a medical "syndrome". Re-naming PMS "pre-menstrual dysphoric disorder" is an attempt to have the condition recognised as a form of depression. And there is evidence that efforts to treat PMS with Prozac, rather than the traditional treatment of the hormone progesterone, are proving effective.

There are also vigorous calls for far more stringent clinical diagnosis of the condition. At present, pre-menstrual syndrome is used as a blanket term by laymen and members of the medical profession alike, to cover a huge assortment of physical and emotional symptoms, from water retention to violent outbursts. This broad definition is one used and promoted by, amongst others, Dr Katharina Dalton one of the early pioneers of PMS treatments, and has prompted a general perception of PMS as something that affects virtually all women and has produced headlines claiming that four in five and 95 per cent of women have PMS. "It is not the case that all women are a rage of hormones at certain times of the month," asserts Dr Precilla Choi, a health psychologist at Keele University. "Very few women have something called PMS."

Maurice Katz, who runs the specialist PMS clinic at Elizabeth Garrett Anderson Hospital in London, says that at least 20 per cent of the women who are referred to him for treatment by their GPs are wrongly diagnosed. Women themselves often wrongly self-diagnose PMS when the cause of their problems may lie somewhere else entirely, for example an unsatisfactory relationship. Precilla Choi says many women actually use PMS as a coping mechanism because it is "more acceptable to blame difficulties on the time of the month than to admit you have, say, a violent partner."

Certainly, anecdotal evidencedemonstrates that there is a widespread view of PMS as routine within the monthly cycle. Women regularly blame outbursts of irritability on PMS. And other people do the same. Many sufferers present PMS as part of being a woman, and one which unites women in a common experience. They feel betrayed by women who deny it. The debate is exacerbated by the fact that there are plenty of women who are not averse to using the excuse when it suits. "Do all the things your non pre-menstrual person would have loved to. Then if any one complains, just say, 'Oh sorry, I've got PMT'," wrote the columnist Barbara Ellen recently.

So many different elements are currently attributed to PMS that quelling the myths is as great a task as finding the facts. Last month, the British Boxing Association banned women from the sport on the grounds that they were unstable and vulnerable before their periods. Myth number one. A leading PMS expert countered that PMS would make better boxers of women, who would be all the more aggressive in the ring. Myth number two. Precilla Choi, who is also a trained sports scientist, says, "all the work on the effect of the menstrual cycle on sport and sportswomen show it has absolutely no effect."

Choi plans to study the effects of stress on the incidence of PMS, which might offer a partial explanation as to why PMS seems so prevalent in industrialised cultures. Meanwhile, researchers at University College Hospital are pioneering a new approach to treating PMS, which joint director Myra Hunter calls '"bio-psycho-social". In addition to medical treatment, a broader strategy deals with other issues in the patient's life, and challenges core beliefs about how women see themselves and their role, as well as their assumptions about menstruation. Trials currently under way to compare the efficacy of therapy and Prozac as treatments.

There is still enormous variance regarding theories as to the causes of PMS. The American Psychiatric Association, for example, are clear that the causes are due to a malfunction of chemical neurotransmitters in the brain. Others think the causes are cultural and/or psychosomatic and yet others, such as Dr Maurice Katz, believe that while progesterone levels are related, a minority of women are simply "born with or develop a pre- disposition to PMS", which is triggered by life events. What is evident is that the time has come for a critical rethink, recognising that PMS is a clinical condition - it is not the female condition.

The Women's Health Research Unit at UCL are looking for volunteers to take part in a study on PMS. Call Susannah Brown on 0171 504 5342.

APOLOGY: In the article, 'When Did You Last See Your Children', published on 15th February, we omitted to provide a contact number for the support group Families Need Fathers. They can be reached on 0171 613 5060