FRIDAY, Feb. 11, 2005 (HealthDay News) -- An extract of the herb St. John's wort was found to be slightly more effective than the widely prescribed antidepressant Paxil for people with moderate to severe depression, a short-term German study found.
The results fly in the face of a large-scale, carefully controlled U.S. trial, reported in 2002, that found a St. John's wort extract was no more effective than a placebo for people with moderately severe depression. The earlier study found statistically significant improvement in patients who took the antidepressant Zoloft, compared to those who took a placebo.
The German results were strikingly different. The study included 251 people with a score of 22 or higher on the Hamilton Depression Scale, a widely accepted measure of the condition. The Hamilton score decreased by 14.4 points for patients who took three daily doses of the St. John's wort extract for six weeks, compared to a reduction of 11.4 points for patients who took Paxil. There were also fewer adverse side effects in the St. John's wort group than in the Paxil group.
The research was financed by the company that markets the extract. The findings appear in the Feb. 12 issue of the British Medical Journal, whose reports are "refereed," meaning their validity is checked by medical experts.
The difference between the German and U.S. results could be explained by a difference in the severity of the condition among participants in the two trials, said Kirstin Stolp, a pharmacist with Dr. Willmar Schwabe Pharmaceuticals, the maker of the extract used in the new study.
"Patients in their [the U.S.] study had a more chronic condition, with the duration of their current episodes of depression much longer than in ours," she said. "Also, patients in the American trial in large part had not responded to several previous attempts at treatment. Our trial included only patients who had only one treatment without response."
The extract used in the German trial is marketed in European countries under the brand name Neuroplant VO, said Dr. Jochen Muehlhoff, marketing information manager for the company. It is sold in the United States as a dietary supplement by Nature's Way products under the brand name Perika, "for promoting a positive mood, rather than a drug for the treatment of depression," he said.
European regulators have approved the product for treatment of "major depression of mild to moderate severity," Muehlhoff said. The newly reported trial "shows for the first time that also severely depressed patients significantly benefit from treatment," he added.
Dr. Carol Kleinman, a member of the American Psychiatric Association, said the brevity of the German study was a matter of concern.
"I noticed that it was only for six weeks," she said. "Paroxetine [the generic name for Paxil] usually is not completely effective in that period. If the study went out in time a little further, the effects of the treatments might distinguish themselves. Paroxetine needs eight weeks to be fully effective."
Nevertheless, Kleinman said, "I think I would be comfortable in prescribing St. John's wort for mild depression, if it was for someone I could follow closely. Some people prefer what they call natural substances. But for moderate to severe depression, it does not work as well."
Kleinman said she is not currently prescribing St. John's wort for any of her patients.
However, Dr. Uriel Halbreich, a professor of psychiatry at the State University of New York at Buffalo, who took part in an earlier U.S. trial of St. John's wort, said he "definitely would not prescribe St. John's wort."
While he called the results of the German trial "quite impressive," Halbreich said there are practical difficulties in the use of St. John's wort, particularly for persons who take an extract on their own.
"If you go to a drug store or vitamin or supplement store, you find a lot of brands, and they are different from each other," he said. "Even with a very reputable German manufacturer, there are differences in activity."
Another problem is the potential for adverse reactions with other medications, Halbreich said. "I would not recommend it to a patient because of the inability to control for drug-drug interactions. Many people who would get the medication without a prescription are taking many other medications. I would advise any patient to be careful of what they take."
More information
The American Psychiatric Association has more on the symptoms and treatment of depression.
