St John's Wort for depression: a systematic review

CRD COMMENTARY: The review addressed a pertinent question with well defined inclusion and exclusion criteria. The literature search was comprehensive in terms of the databases searched and reference lists checked with adequate attempts to identify unpublished material. A flaw in the search strategy was it restriction of articles to those in the English language. Given the authors assertion the 'It (St John's Wort) has long been a popular antidepressant in Germany' it is possible that significant articles may have been missed. The quality assessment of the included studies was adequate although the authors do not state if this was conducted by one or more reviewers, or whether any checking of this assessment was performed. The details of the individual studies are summarised briefly in tables which give the dosage of hypericum extract, name of reference drug where available, number of patients and number of responders with p value. The narrative synthesis of the data appears adequate, although, given that all the placebo comparisons utilise the same outcome measures it is surprising that a quantitative pooling was not performed for these data. The data as presented in this review support the authors conclusions. The review provides only limited information on the adverse effects of St John's Wort.