St. John’s Wort is a yellow-flowered herb used to treat health conditions since the time of ancient Greece. The herb’s scientific name is Hypericum perforatum, and is sold in the United States as a dietary supplement. In Europe, St. John’s Wort is used to treat mild to moderate clinical depression.
St. John’s Wort Clinical Studies
While St. John’s Wort has a long history as a depression treatment, much of its reputation is based on historical use. Clinical trials suggest that while St. John’s Wort has some applications as a treatment for depression, it may not be well suited for all types of depression.
The National Center for Complementary and Alternative Medicine (NCCAM) funded one such study. The results of the NCCAM study were that placebos were as effective as St. John’s Wort for moderate to severe major depression disorder. The same study suggested that the antidepressant sertaline was also no more effective than placebo for depression treatment.
While such studies are discouraging, other research suggests that St. John’s Wort at least has potential as a treatment for mild depression. Further study is required to confirm or disprove this possibility.
How St. John’s Wort Treats Depression
It’s not entirely clear which compounds found in St. John’s Wort help people cope with depression. The two most likely active compounds are the chemicals hypericin and hyperforin, both of which are thought to affect neurotransmitters (compounds in the nervous system that act as chemical messengers). Low neurotransmitter levels appear to affect a person’s mood.
Types of St. John’s Wort
St. John’s Wort comes in three basic forms. Capsules or tablets of the herb are available, as are herbal teas made from St. John’s Wort. Liquid extracts are also available. St. John’s extracts are concentrated distillations of the plant chemical compounds.
Whether choosing teas, capsules or St. John’s extract, bear in mind that herbal and dietary supplements – in the U.S. at least – are not as well regulated as medications. The range of quality and purity from one herbal supplement to the next can vary widely, and it’s wise to bear this in mind when purchasing St. John’s Wort or any other natural remedies for depression.
St. John’s Wort, Side Effects and Serotonin Syndrome
St. John’s Wort is usually safe to use, but can cause unwanted side effects. The most common side effects associated with St. John’s Wort include:
- anxiety
- diarrhea
- dizziness
- dry mouth
- fatigue
- headaches
- insomnia
- irritability
- photosensitivity (sensitivity to sunlight)
- restlessness
- skin rash
- stomach problems
- tingling sensations
- vivid dreams.
St. John’s Wort can also interfere with the effectiveness of certain medications. People should avoid St. John’s Wort if they are prescribed any of the following:
- anticancer medication
- anticoagulants (blood thinners)
- antidepressants
- birth control pills
- cyclosporine
- digoxin
- medications used to treat HIV.
Pregnancy and nursing women should avoid St. John’s Wort, as should anyone trying to conceive children. As the herb affects anticoagulants, people scheduled to have surgery should avoid taking St. John’s Wort for at least two weeks before surgery.
Using St. John’s Wort in combination with certain antidepressants can result in a potentially fatal condition known as serotonin syndrome. Before taking any dietary supplement with prescription medication, be sure to talk to a health care professional about possible interactions.
Other Depression Herbs
In addition to St. John’s Wort, a number of other natural remedies for depression exist, including kava kava and ginko biloba. Clinical studies into the efficiency of these natural treatments for depression are limited.
It cannot be overstated: before choosing natural remedies for depression check their safety with a mental health professional and be sure the dietary supplement does not interact with any prescribed or over the counter medications.
Resources
National Center for Complementary and Alternative Medicine. (Retrieved 19 September, 2009). St. John’s Wort and Depression
RxList. (Retrieved 19 September, 2009). St. John’s Wort
Disclaimer: The information contained within this article is for informational purposes only, and is not intended to be a substitute in any way for care and treatment by a qualified health professional.
Michael McGrath - Michael McGrath began providing web content shortly after finishing his graduate degree in English at the University of Alberta. His broad ...
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