Herbs and pharmaceuticals often do not mix well. During the 1990s, a plant called Saint-John’s-wort became one of the most widely known and widely used herbs in the United States. A shrub with small green leaves and yellow flowers, Saint-John’s-wort seemed to be a safe, natu-ral substitute for many pharmaceutical antidepressants. For centuries, the story went, Europeans drank herbal teas made of Saint-John’s-wort to combat mild cases of depression, especially in northern Europe, where winter nights last longer than they do farther south. Many peo-ple in these regions develop a form of depression called seasonal affec-tive disorder (SAD), which is also called winter depression or winter blues. SAD comes from the decrease in sunlight as the days shorten between mid-fall and early spring, and its symptoms are similar to those of other depressive maladies.
Depression, in psychiatric terms, is not an overbearing feeling of sadness. Instead, it refers to a depressed flow of electrochemical signals through the neurons of the brain caused by a reduction in
neurochem-icals such as serotonin and dopamine. Symptoms of this neurochemi-cal shortage include sleeplessness, difficulty thinking, mood swings, as well as emotional lows. Through chemical reactions inside and between the neurons, antidepressants keep the levels of brain chemi-cals “normal.” From the end of World War II on, psychiatric researchers discovered a wide selection of prescription antidepressants, many of which are described in Chapter 7. These drugs shared the ability to speed up and strengthen the flow of signals through the brain, though at the cost of some annoying side effects.
Saint-John’s-wort supposedly was able to combat depression with-out the side effects of psychiatric drugs, and some people with depres-sion began using the herb instead of, or along with, standard antidepressant medications. Many of the people who used the herb instead of the medications did so because they distrusted pharmaceuti-cals and Western medicine in general, or because of a desire to live a
“more natural” lifestyle. Others were not able to afford psychiatric care and medication, and turned to Saint-John’s-wort as an affordable alter-native. Some patients who were under psychiatric care and were taking antidepressant medications used Saint-John’s-wort as well, believing that the herbal supplement would not affect or interfere with their pre-scribed medications. Most of these people, studies showed, did not tell Saint-John’s-wort, an herb that some people take as a natural antidepressant, has been shown to cause problems when taken in combination with certain
pharmaceutical drugs. (National Plant Data Center/plants.usda.gov)
their psychiatrists or their physicians about their supplemental self-medication.
Without realizing it, these patients were putting themselves at great risk of developing additional problems, perhaps worse than the ones they were trying to treat. Overcoming depression with medicine is a chemical balancing act. Patients have to have a high enough level of antidepressant drugs in their bloodstream to overcome the blood-brain barrier, which prevents foreign substances from entering the brain. Too little of a drug in the patient’s bloodstream and there will be no effect; however, too much of a drug can numb a patient to real-ity, while also threatening to damage the liver, the kidneys, and other organs.
For all of its image as a centuries-old cure from nature, Saint-John’s-wort contains a mix of chemical compounds that supposedly do the same thing as pharmaceutical antidepressants. When patients began taking the herb along with prescribed antidepressants, the chemicals from the two sources enhanced each other, causing a greater reaction in the patients’ brains. Some patients began showing up with signs of antidepressant overdose, although they were taking well-adjusted doses of antidepressants. In rare cases, Saint-John’s-wort even counteracted some pharmaceutical antidepressants, leaving patients feeling as bad as they did before. Even worse was the interaction between Saint-John’s-wort and a class of drugs called protease inhibitors, which help prevent infections of human immunodeficiency virus (HIV) from developing into AIDS. A number of studies showed that the herb cut down the amount of the HIV-suppressing drug that was present in the bloodstream, putting patients at greater risk of developing the disease. Since many HIV patients naturally felt depressed about their condition and the stress it put on them, some of them were taking Saint-John’s-wort without knowing the possible harm they were doing to themselves.
There was, it turned out, no safe way to combine Saint-John’s-wort with any prescribed or OTC medications. As with other herbal prod-ucts, the amounts of Saint-John’s-wort in commercially produced sup-plements varied widely. No minimum or maximum dosages of the herb or of its active ingredients had been determined as of early 2003, though some studies of the herb’s effect used amounts ranging from a few hun-dred milligrams to a gram and a half a day. Because there was no reli-able way to know how much of the herb was too much, manufacturers were asked to include warnings about the plant’s possible problems on their product labels, while pharmacists began including warnings about Saint-John’s-wort in the literature they gave their customers.