A Placebo Controlled Clinical Trial of a Standardized Extract of Hypericum Perforatum in Major Depressive Disorder

This trial will determine the acute antidepressant efficacy of a standardized extract of hypericum (St. John's Wort) for the treatment of major depressive disorder. For this trial, the primary efficacy analysis will be evaluated at 8 weeks. For observational purposes, a 4-month double blind continuation (6 months total treatment) in treatment responders would enable an approximation of the effectiveness of maintenance treatment with this medication. No published studies have included a selective serotonin re-uptake inhibitor (SSRI) comparator. While this trial will not compare the efficacy of hypericum to an SSRI, having an SSRI arm of sertraline (Zoloft) will allow an evaluation of the validity of the trial. 336 eligible patients will be randomly assigned to double-blind treatment with hypericum, sertraline, or placebo following a one-week placebo lead-in period (between screening and baseline). All treatment groups will consist of 112 patients and will be followed for an eight-week period. Treatment responders will be continued on the randomly assigned treatment arm for an additional 18 weeks.