A very quick google scholar search revealed this:

Titre du document / Document title
St John's wort for depression: A systematic review
Auteur(s) / Author(s)
GASTER B. (1) ; HOLROYD J. (1) ;
Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)
(1) Department of Medicine, University of Washington, Seattle, ETATS-UNIS

Résumé / Abstract
To address whether St John's wort is useful for the treatment of depression we attempted to retrieve all English-language articles with data on the efficacy, safety, and availability of St John's wort. Randomized, controlled, double-blind trials were selected and assessed for methodological quality using a standardized checklist, and data on pharmacology, cost, regulation, and safety were extracted. Eight studies were identified, found to be of generally good methodological quality, and determined to provide a modest amount of data to suggest that St John's wort is more effective than placebo in the treatment of mild to moderate depression. The absolute increased response rate with the use of St John's wort ranged from 23% to 55% higher than with placebo, but ranged from 6% to 18% lower compared with tricyclic antidepressants. More data are required to assess both its use in severe depression and its efficacy compared with other antidepressants. Rates of side effects were low. As a dietary supplement, St John's wort is currently largely unregulated, but the Food and Drug Administration is reviewing plans to tighten its regulatory oversight.
Revue / Journal Title
Archives of internal medicine (Arch. intern. med.) ISSN 0003-9926 CODEN AIMDAP
Source / Source
2000, vol. 160, no2, pp. 152-156 (40 ref.)

That was in 2000. I don't know what research has been done since then...

So...

I guess the question is...

Who is sponsoring you? Lilly?

;-)