Study designs of evaluations included in the review
Crossover and parallel-group randomised controlled trials (RCTs) were eligible for inclusion in the review.
Specific interventions included in the review
Studies that compared an active treatment with a placebo or comparison treatment taken continuously or premenstrually over at least a 1-month cycle were eligible for inclusion. Studies that evaluated combinations of treatments were excluded. The included studies evaluated calcium, vitamin B6, magnesium, evening primrose oil, Vitex agnus castus, St. John's Wort and gingko biloba, and compared these treatments with placebo. The duration of treatment ranged from one cycle to 12 months.
Participants included in the review
Studies of women of reproductive age with a retrospective or prospective diagnosis of PMS or premenstrual dysphoric disorder were eligible for inclusion. The participants had to be without other pre-existing psychiatric conditions but they could have depression or anxiety that was only present premenstrually. Women taking the oral contraceptive pill were eligible.
Outcomes assessed in the review
Studies that assessed combined PMS symptoms, global scores or specific symptoms were eligible for inclusion. Where specified, the included studies measured outcomes using symptom change, symptom complex scores, the Mental Health Questionnaire, Menstrual Distress Questionnaire, congestive symptoms and visual analogue scales. The outcomes were measured by patients or assessed by medical practitioners.
How were decisions on the relevance of primary studies made?
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.