What Is the Scientific Evidence for St. John’s Wort?
Depression There have been two main kinds of studies: those that compared St. John’s wort to placebo, and others that compared it to prescription antidepressants. A 2008 detailed review of 29 randomized, placebo controlled trials found that St. Johns wort was consistently more effective than placebo and equally effective to standard antidepressants.133 St. John’s Wort Versus Placebo • Studies of St. John’s wort (and other antidepressants) use a set of questions called the Hamilton Depression Index (HAM-D). This scale rates the extent of depression, with higher numbers indicating more serious symptoms. • Double-blind, placebo-controlled trials involving a total of more than 1,500 participants with major depression of mild to moderate severity have generally found that use of St. John’s wort can significantly reduce HAM-D scores as compared to placebo.21-28,89,105,123 In addition, continued treatment with St. Johns Wort over 6 months may be effective at preventing a relapse of moderate d
