Even this suggestion arouses ire. There is a widespread misperception that saying something is in the mind is tantamount to saying it does not exist. Yet mental symptoms are as real as the physical kind (and may themselves trigger physical symptoms) but are rarely accorded the same status. In addition, they carry a stigma based on the prejudice that they are in some way self-created.
Researchers in the field are now beginning to confront this prejudice. Evidence from the United States suggests that Prozac, the antidepressant drug, is the most effective treatment to date for women with PMS. However many women feel that continuous treatment with Prozac for symptoms that occur once a month is not a satisfactory answer.
In Britain, psychologists have begun a trial comparing Prozac with psychological therapy to treat mental symptoms. The study, the first of its kind in the UK, is being conducted by the Women's Health Research Unit at University College, London, which has a reputation for ground-breaking feminist research. It was criticised yesterday by Dr Katherina Dalton, consultant gynaecologist and doyenne of PMS research, for pre-judging the outcome.
"The right way to conduct a trial is to have one group who receive no treatment. Here they seem to have made up their minds what works. I wonder whether they are really looking at PMS or only the psychological symptoms of PMS."
According to Dr Dalton, some women experience attacks of asthma, epilepsy and migraine once a month linked with their periods. Others suffer acne and glaucoma, a condition caused by raised pressure within the eyeball. "All the counselling in the world won't make a difference to that," she said.
Dr Dalton was the first doctor to describe pre-menstrual syndrome in 1953 and has achieved fame and a degree of notoriety since. She has appeared as a witness for the defence in at least half a dozen trials of women accused of murder and arson and helped them escape conviction on the grounds that the balance of their mind was disturbed at the time of the offence as a result of PMS.
Despite four decades of research, pre-menstrual syndrome remains one of medicine's great mysteries. Like Chronic Fatigue Syndrome and most cases of backache, neither its cause nor its cure are understood. Nine out of 10 women of child-bearing age are thought to suffer from physical or psychological symptoms prior to the onset of their period. For most the symptoms are mild, including breast swelling or feelings of bloatedness but one in 10 find the experience severely debilitating and may be unable to cope with families or work.
Dr Dalton says that the best approach for those seriously affected is a combination of hormonal treatment and diet. "I would say very firmly that the correct treatment is to give progesterone combined with a three- hourly starch diet. If there are long gaps between food, the blood sugar falls, symptoms worsen and the progesterone receptors become used up. Giving progesterone without regular snacks is useless."
A sandwich or biscuits every three hours is all that is necessary to keep blood sugar levels maintained. The diet should not result in weight gain so long as the same total calorie intake is spread throughout the day. "Women need to eat little and often as they used to in the old days. When they were at home cooking they would be tasting all day, as well as having a mid-morning coffee, tea in the afternoon and a late-night snack. It is only this generation of women who do not eat three hourly," she said.
However, psychologists at the Women's Health Research Unit say there is "little evidence" that hormonal treatments work and that treatments based on diet and exercise are impractical "given today's woman's balancing act between family and work".
Vitamin and mineral supplements are expensive, they add. A new approach is needed, they say: although opposed to the view that the syndrome is all in the mind, psychiatric or psychological treatments hold out greater promise. The unit's study, which has been running for a year, has recruited half its target figure of 120 volunteers. A third of the group are given Prozac, a third eight sessions of psychological therapy (which includes relaxation, stress management and assertiveness training), and the remaining third a combination of the two. The results will be published in 18 months.
Dr Myra Hunter, clinical psychologist and director of the unit, said: "Views on the syndrome are polarised. No one really knows what it is. We are trying to combine biological, psychological and social approaches. It is not all in the mind or all in the body. People with it are not mad and it's not their hormones - it is a complex interaction of all these things."
Prozac counted as a biological, not a psychological, approach to treatment because it was based on the view that the hormonal fluctuations that precede the monthly period affect levels of the brain chemical serotonin, which is implicated in depression. Giving Prozac could arguably be seen as a treatment for lowered serotonin levels, rather than as a treatment for depression, and this made it easier for women to accept, she said.
Dr Hunter said that the worst-affected women tended to have a lot of stresses in their lives. "Some express their distress in depression - others soldier on. In some their threshold for coping is lower - they manage for most of the month but not when they are pre-menstrual."
Researchers at the unit say there are wide variations in the skill and sympathy with which family doctors treat PMS. Some women are told that the syndrome does not exist or is all in the mind. Others are warned they may need a hysterectomy or that there is no treatment available.
Not everything labelled as PMS qualified as a genuine symptom of the condition, Margaret Wall of the National Association for Premenstrual Syndrome, a charity for sufferers, said. "It could be stress in people's lives," she added.
However, evidence from carers of mentally handicapped women who were unable to communicate but displayed signs of distress regularly each month suggested there was a real syndrome. "If people who are not influenced by events [because they live in a protected environment] and are not subject to the normal stresses of life still experience the symptoms then that suggests there is something going on. The arguments over PMS keep coming round, and I guess they will continue to do so."n
The National Association For Premenstrual Syndrome helpline can be contacted on 01732 741709. To volunteer for the Women's Health Research Unit study call 0171-380 7585