Overview
St. John's Wort (Hypericum perforatum, 圣约翰草) is the most commonly used herb in USA and in Europe to maintain a positive mood. It is prescribed in Germany 20 times more often than Prozac for treatment of depression. Clinical research has shown that standardized St. John’s Wort extract helps improve symptoms related to depression.† (see latest clinical trial news) It has few side effect. However, caution needs to be taken if you are taking other prescription drugs because drug interactions have been noticed.

St. John's Wort Health Benefits
Many clinical trials have been conducted by researchers in USA and Europe to evaluate the use of St. John's Wort as antidepressant. In a meta analysis of St. John's Wort clinical trials, 23 randomized, placebo or antidepressant drug controlled trials were identified, of which 20 trials were further double blinded. The analysis revealed that all but two trials showed that St. John's Wort is significantly superior to placebo and is as effective as antidepressants in the treatment of mild and moderate depression.¹

In a subsequent, well publicized trial funded by NIH, however, St. John's Wort was found no better than placebo.¹ What the media failed to mention to the public was that in the same trial sertraline, a standard antidepressant approved by FDA, was no better than placebo too, which means even a known antidepressant did not work in the trial, suggesting the trial simply did not work and does not actually tell anything about St. John's Wort. It is noteworthy that in the trial the patients are all in major depressive disorder.²

It comes to 2005 when a new and well publicized trial was released. Here 251 patients with acute major depression were randomized to receive either a St. John's Wort standardized extract, or popular antidepressant drug Prozac in a double blinded manner.³ Both St. John's Wort and Prozac were used in their standard dose for 6 weeks. The results shows that St. John's Wort is at least as effective as Prozac in the treatment of depression yet has less side effect.³ (see related news)

Active Ingredients
Research on St. John's Wort mostly uses standardized extracts made from its dry flowers and stems. The standardized extracts are concentrated 5-7 times and typically contains 0.3% hypericin, which is believed to be the active ingredient of St. John's Wort. Sometimes St. John's Wort extracts are standardized to 2-4.5% hyperforin, which was suggested by some research to be the active ingredient. Nevertheless, most research and clinical trials have used standardized St. John's Wort extract at 0.3% hypericin.

Dose and Duration
In the St. John's Wort clinical trials, patients typically took 900 mg standardized extract per day, divided in 3 times. In case the body is not responding, the dose were often raised to 1800 mg. The trials commonly last for 6 to 8 week. ^1-3

St. John's Wort Side Effects
Side effects are few in the St. John's Wort clinical trials and less common than the antidepressant drugs such as Prozac.^1-3 However, the following mild adverse reactions were occasionally observed: upper abdominal pain, diarrhoea, dry mouth, nausea, fatigue, dizziness, headache, sleep disorder and sweating.

St. John's Wort Drug Interaction
Numerous studies suggest that St. John's Wort may interact with other prescription drugs to weeken their effects. Examples may include: anti-HIV drug indinavir, the immunosuppressant drug cyclosporine, anticoagulants like warfarin, anti-cancer drugs like irinotecan. So caution needs to be taken if you are on other medications.

News

Easing Depression Without Drugs May 02, 2005 BusinessWeek

Herbal Remedy as Good as Drug for Depression: Study Feb 11, 2005 Reuters

Study: St. John's Wort Useful for Depression Feb 10, 2005 Fox News

St. John's Wort May Interfere with Cancer Drug Nov 08, 2004 Reuters

St. John's Wort May Cut Levels of Heart Drug Jun 30, 2004 Reuters

St. John's Wort Weakens Cancer Drug's Effect Aug 20, 2002 Reuters

Study Shows St. John's Wort Ineffective for Major Depression of Moderate Severity Apr 09, 2002 NIH

NIH Clinical Center Study Demonstrates Dangerous Interaction Between St. John's Wort and an HIV Protease Inhibitor Feb 10, 2000 NIH

Reference
1. Linde K, Ramirez G, Mulrow CD, Pauls A, Weidenhammer W, Melchart D. St John's wort for depression--an overview and meta-analysis of randomised clinical trials. BMJ. 1996 Aug 3;313(7052):253-8.
2. Hypericum Depression Trial Study Group. Effect of Hypericum perforatum (St John's wort) in major depressive disorder: a randomized controlled trial. JAMA. 2002 Apr 10;287(14):1807-14.
3. Szegedi A, Kohnen R, Dienel A, Kieser M. Acute treatment of moderate to severe depression with hypericum extract WS 5570 (St John's wort): randomised controlled double blind non-inferiority trial versus paroxetine. BMJ. 2005 Mar 5;330(7490):503.

by X. Li, Ph. D. (credential)