St. John's Wort

Research studies.   St. John's wort, probably the most widely publicized of the herbal supplements for mental health, has strong support in the research literature. An article by Dr. Michael Murray found more than two dozen studies in which the herb was used with depression symptoms with overall consensus of effectiveness in treating mild to moderate symptoms.

The only apparent controversy regarding the effectiveness of this supplement is in whether it is also effective in treatment of symptoms of major depression. A study completed in 2001 and widely quoted in the popular press concluded that the herb was not effective for treatment of major depression. The authors acknowledged difference in their findings from those in prior research but suggested that most of the other studies had significant flaws in the research designs. A panel convened to review the results, however, reconfirmed St. John's wort as safe and beneficial for mild to moderate depression, stress and anxiety. They emphasized caution in generalizing from subject pools limited to participants with major depressive disorders.

In context, as a researcher, I would further note that some controversy in interpretation of clinical studies is not unusual, and certainly not limited to studies with St. John's wort. In fact, while the authors in the JAMA article raised questions about the methodology in prior studies, some questions about their own research design were evident in an analysis of their study that I prepared for my students in a graduate research methods course.

Target Symptoms and Dosage.   There is no evidence of a direct link between use of St. John's wort and enhanced sexual function, but its target symptoms, depression and anxiety, may inhibit both desire and performance. The standard dosage recommendation is 300 mg 3 times a day using an extract standardized to contain 0.3% hypericin. A few weeks of usage is typically required before a difference in symptoms will be evident.

Side Effects and Contraindications.  Even critics suggest that St. John's wort appears to be safe and well-tolerated by most of the population, a report certainly consistent with my personal experience with this supplement. A small percentage of individuals have reported mild stomach discomfort, a rash, feeling tired, feeling restless.

A primary caution involves possible interaction with prescribed psychotropics you are already taking. Consulting the prescribing physician is a crucial factor before either substituting or adding the St. John's wort supplement to current medication. Persons with bipolar disorder should be especially cautious with possibility that the increased serotonin from the herbal supplement could trigger a manic episode.

Summary.  All things considered, St. John's wort appears a remarkably safe supplement for most adults with relatively small risk of unwanted side effects and remarkably high probability of some degree of symptom remission. At the time of this writing, no deaths due to St. John's wort toxicity have been reported which, unfortunately, is not the case for some synthetic antidepressants. While targeted for depression and anxiety symptoms, one could also reasonably anticipate that the supplement could be helpful for other problems in which an underlying depression or anxiety is contributing to the behavioral symptoms.


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