Why serotonin could hold the key to ending the monthly madness

Last week, Prozac was officially licensed as a treatment for Premenstrual syndrome. Licences for similar drugs, such as Seroxat, which Kate Evans was prescribed, are likely to be follow. Shaughn O'Brien, professor of obstetrics and gynaecology at Keele University and North Staffordshire Hospital, is conducting an on-going study into the use of Selective Serotonin Re-uptake Inhibitor (SSRI) drugs in the treatment of PMS. He explains that PMS symptoms are linked to progesterone release at ovulation, mid- point in the menstrual cycle. "Nobody has ever found a difference in progesterone levels between women who have PMS and women who don't," he says. "So the current hypothesis is that PMS is down to the way women respond to the hormone. Women with PMS react more strongly."

Last week, Prozac was officially licensed as a treatment for Premenstrual syndrome. Licences for similar drugs, such as Seroxat, which Kate Evans was prescribed, are likely to be follow. Shaughn O'Brien, professor of obstetrics and gynaecology at Keele University and North Staffordshire Hospital, is conducting an on-going study into the use of Selective Serotonin Re-uptake Inhibitor (SSRI) drugs in the treatment of PMS. He explains that PMS symptoms are linked to progesterone release at ovulation, mid- point in the menstrual cycle. "Nobody has ever found a difference in progesterone levels between women who have PMS and women who don't," he says. "So the current hypothesis is that PMS is down to the way women respond to the hormone. Women with PMS react more strongly."

Many studies have shown that around five to eight per cent of women have extremely severe physical and psychological symptoms. American psychiatrists have classified this extreme as Premenstrual Dysphoric Disorder (PMDD), and it is for treating PMDD that Prozac was licensed last Tuesday. "The theory is that patients with PMS are lacking a neurotransmitter in the brain, and this makes them sensitive to progesterone," explains Professor O'Brien. "This could be a lack of endorphins, or it could be dopamine, but the most convincing evidence points to serotonin. The evidence is indirect - women with PMS have been shown to have lower blood levels of serotonin, but it's impossible to measure brain levels. But extensive studies have shown that when serotonin in the brain is boosted using SSRI drugs such as Prozac, Seroxat or Lustral, symptoms get better." It is likely that Seroxat and Lustral will also be licensed soon for the treatment of PMDD. "These drugs are expensive and budget-conscious GPs may refuse to prescribe them if they are not officially licensed," says Professor O'Brien. "Now they will have less of a leg to stand on."

National Association for Premenstrual Syndrome helpline (tel: 01732 760012). Website: www.pms.org.uk