The Effectiveness of St. John’s Wort in Major Depressive Disorder

A continuation study of an extract of St. John's wort (Hypericum perforatum) for depression was performed in follow-up to an acute study that found no significant difference between St. John's wort extract and placebo.Seventeen subjects with DSM-IV-defined major depressive disorder who responded to St. John's wort extract in the acute-phase study (phase 1) were continued on double-blind treatment with the same preparation for 24 weeks. Ninety-five subjects who did not respond to either St. John's wort or placebo were treated with an antidepressant for 24 weeks.During antidepressant treatment, mean scores on the Hamilton Rating Scale for Depression for phase 1 nonresponders decreased significantly (p <.0001), with no significant difference between St. John's wort nonresponders and placebo nonresponders. Of the 17 subjects continued on treatment with St. John's wort extract, 5 (29.4%) relapsed.The subjects who did not respond to St. John's wort extract or placebo in phase 1 were, by and large, not resistant to antidepressant treatment. This suggests that the lack of efficacy found by Shelton et al. in the acute-phase study was unlikely to be the result of a high proportion of treatment-resistant subjects.