Hypericum Perforatum in the Treatment of Mild Depression


M. Nordfors and P. Hatvig






Extracts of Hypericum perforatum St. John's wort, have been used since antiquity for the treatment of depressive symptoms. In 25 controlled clinical trials where hypericum extract was compared with placebo and established antidepressants, improvement was obtained in 61 percent of patients on low-dose treatment (< 1.2 mg hypericum extract), and in 75 percent of patients treated with a higher dose (2.7 mg). The side effects were mild and occurred at lower frequency than did those of other antidepressants. The constituent of hypericum extract that is responsible for the antidepressant effect has not been identified. Nor is the mechanism of action known, but a combination of low-grade monoamine oxidase inhibition and noradrenaline and serotonin reuptake blockade seems the most likely alternative, though other interesting mechanisms have also been proposed. Owing to their beneficial effect and low toxicity, preparations containing extracts from H perforatum might furnish an alternative to established therapy, especially among patients concerned about stigmatization or less apprehensive of herbal medication than of synthetic drugs.