St. John's Wort and Hypomania

Sir: The herbal remedy St. John’s wort (Hypericum perforatum) has gained increasing attention as a treatment for depression. Several European studies support the efficacy of St. John’s wort in treating mild-to-moderate depression; however, interpretation of these findings has been limited by methodological problems in the existing research. The mechanism of action of St. John’s wort is unknown, although serotonin reuptake inhibition has been suggested as a basis for its mood elevating effects.