Effectiveness of St. John’s Wort (Hypericum Perforatum) vs. Placebo or Other Antidepressants in the Treatment of Mild to Moderate Depression: A Meta-Analysis of Randomized Control Trials
Creators: name: Hooker, James Benjamin
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: Background: Depressive disorders, including mild to moderate depression, are common illnesses that affect an estimated 1 in 5 individuals and account for substantial societal and individual costs. Cost is one barrier to an individual seeking treatment for depression with standard antidepressants. A more affordable antidepressant could lessen this barrier to the treatment of mild to moderate depression. Inexpensive extracts of the flowering plant Hypericum perforatum (St. John’s wort or SJW) have long been used as an alternative treatment for depression. While the popularity of SJW has been growing in the US, there is still doubt as to its effectiveness. The purpose of this review is to examine the effectiveness of SJW alone compared to placebo or to other antidepressants in the treatment of mild to moderate depression. Methods: I conducted a literature search for randomized clinical trials of human subjects published in English between 1998 and 2004 using MEDLINE, BIOSIS v3.0, Alt Health Watch, AMED, and CINAHL. I used the key words “antidepress*,” “depress*,” “hyperic*,” “john’s wort,” “johns wort,” “johnswort,” “blind*,” “random*,” “clinical trial,” “rct,” and “placebo.” To be included in the analysis, a study must: 1) randomize subjects, 2) compare SJW alone to either placebo or other antidepressant, 3) enroll subjects >= 18 years old, 4) use the Hamilton Depression Rating Scale (HAM-D) to measure outcome, 5) study patients with mild to moderate depression, and 6) define “response” as one whose HAM-D score decreases by >50% from baseline or is <= 10 at the end of the trial. I excluded studies with subjects under 18 years old and those that used a different definition for “response,” did not compare SJW to placebo or other antidepressant, or included subjects with depressive disorders other than mild to moderate depression. Once I extracted relevant data from each trial, I performed a meta-analysis using the MIX 1.7 program. Results: Of 68 articles identified through the literature search, 12 studies met a priori criteria for inclusion in the analysis. Five studies compared SJW to placebo, 5 studies compared SJW to other antidepressants, and two studies compared SJW to both placebo and another antidepressant. Five of 7 studies reported SJW was significantly more effective than placebo in treating mild to moderate depression. These 7 studies included 1510 subjects, lasted 6 to 8 weeks, and used doses of SJW ranging from 500 to 1500-mg per day. Tests for heterogeneity among studies were not significant. The test for publication bias was also not significant. Meta-analysis produced pooled outcomes measure for three comparisons. Significant difference in response was found between SJW and placebo, but not between SJW and other antidepressants, or SJW and SSRI. Discussion: Results of this analysis of 12 studies suggests that treatment with SJW is significantly more effective than placebo and equivalent to other antidepressants, and SSRI’s, in treatment of adults with mild to moderate depression. The strength of these conclusions is lessened by the small sample of included studies. As the popularity of SJW continues to grow, further studies will be necessary to determine a standard dosing regimen and to study adverse effects and to better study effectiveness. There is not currently enough of a database of adequate trials to draw final conclusions on SJW effectiveness versus placebo or other antidepressants. In spite of these limitations, SJW potentially offers a less expensive alternative to standard antidepressant medications.