Altering the Brain's Chemistry - Phytomedicine Considerations
Phytomedicine Considerations
* St. John's wort (Hypericum perforatum) as a standardized extract is licensed in Germany and other European countries as a treatment for mild to moderate depression, anxiety and sleep disorders.
St. John's wort has a complex and diverse chemical makeup. Hypericin and pseudohypericin have received most of the attention based on their contributions to both the antidepressive and antiviral properties of St. John's wort. This explains why most modern St. John's wort extracts are standardized to contain measured amounts of hypericin. Recent research, however, indicates that the medicinal actions of St. John's wort can be ascribed to other mechanisms of action and also to the complex interplay of many constituents.
While St. John's wort's ability to act as an antidepressant is not fully understood, previous literature points to its ability to inhibit MAOs. MAOs act by inhibiting MAO-A or -B isozymes, thereby increasing synaptic levels of the biogenic amines, especially norepinephrine. This earlier research showed that St. John's wort extracts not only inhibit MAO-A and MAO-B but also reduce the availability of serotonin receptors, resulting in the impaired uptake of serotonin by brain neurons.
More than 20 clinical studies have been completed using several different St. John's wort extracts. Most have shown antidepressant action either greater than placebo or equal in action to standard prescription antidepressant drugs. A recent review analyzed 12 controlled clinical trials - nine were placebo-controlled and three compared St. John's wort extract to antidepressant drugs maprotiline or imipramine. All trials showed greater antidepressant effect with St. John's wort compared with placebo and comparable results with St. John's wort as with the standard antidepressant medications. The first U.S. government-sanctioned clinical trial of St. John's wort, a three-year study sponsored by the Center for Complementary and Alternative Medicine, based in Washington, D.C., found that St. John's wort was not effective in treating major depression, but agreed more clinical trials were needed to test the herb's effectiveness in mild to moderate depression.
Dosage is typically based on hypericin concentration in the extract. The minimum daily hypericin dosage recommended is approximately 1 mg. For example, an extract standardized to contain 0.2 percent hypericin would require a daily dosage of 500 mg, usually given in two divided dosages. Clinical studies have used a St. John's wort extract standardized to 0.3 percent hypericin at a dose of 300 mg three times daily.
The German Commission E Monograph for St. John's wort lists no contraindications to its use during pregnancy and lactation. However, more safety studies are needed before St. John's wort is recommended for this population.
Ginkgo (Ginkgo biloba) extract, while clearly not a primary treatment of choice for most patients with major depression, should be considered an alternative for elderly patients with depression resistant to standard drug therapy. This is because depression is often an early sign of cognitive decline and cerebrovascular insufficiency in elderly patients. Frequently described as resistant depression, this form of depression is often unresponsive to standard antidepressant drugs or phytomedicines like St. John's wort. One study showed a global reduction in regional cerebral blood flow in depressed patients older than 50 when compared with age-matched, healthy controls.
In that study, 40 patients, ages 51 to 78, with a diagnosis of resistant depression (insufficient response to treatment with tricyclic antidepressants for at least three months), were randomized to receive either Ginkgo biloba extract or placebo for eight weeks. Patients in the ginkgo group received 80 mg of the extract three times daily. During the study, patients remained on their antidepressant drugs. In patients treated with ginkgo, there was a decline in the median Hamilton Depression Scale scores from 14 to 7 after four weeks. This score was further reduced by 4.5 at eight weeks. There was a one-point reduction in the placebo group after eight weeks. In addition to the significant improvement in symptoms of depression for the ginkgo group, there was also a noted improvement in overall cognitive function. No side effects were reported.
Many nutrition-oriented practitioners have found that the answer to depression is as simple as one's diet. A diet low in sugar and refined carbohydrates (with small, frequent meals) can produce symptomatic relief in some depressed patients. Individuals most likely to respond to this dietary approach are those who develop symptoms in the late morning or late afternoon or after missing a meal. In these patients, ingestion of sugar provides transient relief, followed by an exacerbation of symptoms several hours later.
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reviewed by:
Harry Croft, MD (Psychiatrist)
Medical Director, HealthyPlace.com
Created on December 11, 2008 Last Updated on November 30, 2011
In Depression
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