Karen is the midforties woman with the solid marriage, children she adores, and stable home life whose persistent feelings of depression both bewildered her and made her feel guilty, as if she should snap out of it. As I had recommended, Karen had a thorough physical exam. Her overall health was very good, and her hormone levels were just slightly below normal ranges, not low enough for her to want to take replacement hormones now. She also hesitated to take the antidepressant medication that her health care provider suggested.

“This may seem silly or like I’m in denial, but somehow I have this feeling that taking antidepressants is for people who are really much worse off than I am. I’d rather wait and see if these feelings will pass on their own, or take something less intimidating than antidepressants.”

Karen’s sister had given her a book on the herb St. John’s wort, which is reported to be very effective in treating mild to moderate depression. Like black cohosh, St. John’s wort has been well researched and is widely prescribed in Germany. Karen found the idea that an herb might help lift her depression appealing, and she called her health care provider to ask about it: “There was a little beat of silence on the other end of the phone. But when I said I’d like to try it for a couple of months to see if it made a difference, he said he respected my choice and didn’t see any harm in it. Actually I think he might be curious too.”

The active ingredient in St. John’s wort, a perennial plant, is hypericin. It was originally believed that St. John’s wort inhibited a type of brain enzyme called monoamine oxidase (MAO). Dampening MAO levels is the principle behind a very powerful group of drugs called MAO inhibitors. But as more research on St. John’s wort has been done in Europe, it appears now that this herb may inhibit serotonin reuptake.

You’ll remember that serotonin is the brain chemical with a significant influence on mood. When reuptake of serotonin is inhibited, the chemical’s “feel good” effects in the brain last longer. Drugs such as Prozac, Zoloft, and Paxil belong to the class of medications known as selective serotonin reuptake inhibitors, or SSRIs.

Karen started taking a standard extract of St. John’s wort (0.3 percent hypericin), beginning with the standard dosage of 300 mg three times daily. She took it with meals to minimize the possibility of gastric upset. “I feel good,” she said with enthusiasm when I called to see how she was doing a month later. “For one thing, I’m glad I had a physical so I can be assured nothing is wrong with me. It also gave me more of a sense of control to decide to try St. John’s wort first before I go on to anything else. Maybe I won’t need anything else, because I really do feel like there’s less of a cloud hanging over me. When I felt that way, there was usually nothing I could really put my finger on, but I just knew I wasn’t myself.”

Karen said she wouldn’t call St. John’s wort a miracle, but one measure of how it was working for her after only four weeks might be that her husband and one of her children noticed a change: “My husband said, ‘You seem more like yourself.’ I also heard my oldest daughter tell one of her friends on the phone that yes, maybe I would drive them somewhere, because I’ve been in a better mood lately.” She gave a slight laugh. “I guess the ultimate barometer of how I’m doing is my teenager’s assessment of my mood,” she said drily.

Because Karen has olive skin and very dark hair and eyes, she doesn’t have to be cautious about sensitivity to sunlight, which St. John’s wort causes in animals that graze on the plant. But even though photosensitivity has not been reported in humans, fair-skinned individuals with light skin and eyes are advised to avoid strong sunlight and other ultraviolet light when they are taking St. John’s wort.

While much of the attention focused on St. John’s wort examines its use to alleviate depression, this herb may be useful in reducing anxiety as well. As more is understood about the effect of St. John’s wort on serotonin levels and mood, we stand to see substantial increase in its application and use in this country. But I am somewhat concerned about branding St. John’s wort as the alternative to Prozac for two reasons. First, we don’t yet know that St. John’s wort will be effective in helping severely depressed people, it appears most effective in people with mild to moderate depression. Second, I am no more comfortable with widespread, cavalier, uninformed use of an herbal preparation than I am with such use of a prescription medication, so I worry about the idea that we can all take an herb, or a pill of any kind for that matter, and expect it to put our lives in order.

Black cohosh is used in connection with hot flashes and anxiety, among other perimenopausal symptoms. But the German research shows that this herb also reduces feelings of depression in perimenopausal women. When using black cohosh for depression, the dosage is two 40 mg tablets per day.