Controlled clinical trials of hypericum extracts in depressed patients: an overview

CRD COMMENTARY: The author has stated the research question and some inclusion criteria for the review. The literature search is poor because the author has searched only the MEDLINE database and does not report the dates and keywords used. It is not stated whether there were any language restrictions, hence it is possible that relevant studies may have been missed. The author has not reported on how the articles were selected, or how the quality of the included studies was assessed and there is no report as to who, or how many of the reviewers, selected the articles or extracted the data. The studies are not statistically combined, although the study designs are controlled double-blind trials. The results table does not report measurements of change in the outcome measures. There is no discussion or test for homogeneity. The author mentions several drawbacks about the quality and design of the individual studies, including the inclusion scores for HAMD being set too low, the length of treatments being too short, and the doses of active controls being too low (75 mg/day, rather than the usual 150 mg/day) which could influence the strength of the reported results. The reported outcomes should be viewed with caution.