| Summary: | Premenstrual syndrome (PMS) is a prevalent condition. Key symptoms which promote treatment seeking are primarily psychological e. g. depression and aggression. Sufferers are often reluctant to take prescribed medication and often purchase dietary supplements and herbal remedies over the counter for which the evidence base with regards efficacy is limited. The primary aim of this thesis was to examine the effectiveness of St. John's Wort (SJW) for PMS. Proposals that this herbal remedy could benefit PMS symptoms are based on evidence that SJW increases serotonin levels and suppresses pro-inflammatory cytokine production. Following a systematic review which demonstrated that although calcium and continuous vitamin B6 administration confer some benefit for premenstrual symptoms, the evidence for most dietary supplements and herbal remedies including SJW is conflicting or insufficient, a ten-cycle randomised double-blind, placebocontrolled, crossover trial was conducted. PMS sufferers (NIMH, 1983) were administered 900mg SJW/day (0.18% hypericin; 3.38% hyperforin) for two menstrual cycles (n=34). SJW was found to benefit physical and behavioural PMS symptoms, but did not significantly improve mood or pain symptoms. A comparison of various commonly used analytical strategies performed on the data highlighted the need for a consensus to be reached regarding the way in which researchers assess treatment efficacy. Hormone (FSH, LH, oestradiol, progesterone, prolactin and testosterone) and cytokine (IL-1p, IL-6, IL-8, IFN-y and TNF-a) levels were assessed in women with and without PMS during the follicular and luteal phases, and were also studied in PMS sufferers taking SJW and placebo treatment. The hormone and cytokine profiles of PMS sufferers during SJW and placebo treatment did not differ. However, PMS sufferers exhibited significantly greater testosterone and cytokine (IL-6,11-8 and TNF-a) levels than normally cycling women who did not self-report problematic PMS symptoms across the cycle, suggesting that these mechanisms may be involved in the aetiology of the syndrome. To ensure the scientific quality of the clinical trial, certain methodological considerations were explored. PMS is diagnosed in various ways, which has resulted in PMS studies being conducted on heterogeneous samples of women, who are often not analogous to women requiring treatment in clinical practice. This study highlighted the need for researchers to use a diagnostic procedure that identifies PMS sufferers experiencing PMS symptoms at a severity appropriate to address the aim of their study, and that differentiates women with PMS from those with clinical anxiety and depression. Moreover, the DSR (Freeman et al., 1996) was refactor analysed and a two factor solution was produced, the DSR-20. This new measure was shown to be a more sensitive tool than the original DSR to assess treatment effects in the sample recruited for this research. Collectively these findings could improve future diagnostic and therapeutic strategies.
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