Hypericum is effective
The results of this review imply that hypericum is effective in alleviating the symptoms of a variety of depressive disorders. Only two studies conducted against a placebo contradict this notion (Lehr and Woelk 1993, Osterheider et al. 1992). One (Osterheider) was published as an abstract only (thus essential details are lacking for a meaningful interpretation), and both failed to receive a quality rating high enough for inclusion in this review. Thus, almost all placebo-controlled studies reviewed above demonstrate that hypericum is superior to a placebo in treating depression.
The studies conducted against standard antidepressants suggest that the therapeutic effect of hypericum is similar to that of Imipramine or Maprotiline. Taken together, these data are scientifically compelling and leave little doubt as to the efficacy of hypericum in the treatment of depressive symptoms.
Some critical points ought to be raised. Most of the studies have been published recently, virtually all in German and many in journals that might be unfamiliar to an international audience. Photomedicine has clearly more of a domain on the Continent than in Britain or the US; the money annually spent on the Continent per capita on prescribed herbal monopreparations, for instance, is one order of magnitude more than in the UK (De Smet 1993).
Thus it is understandable that much of the literature relating to this topic should be published in German journals. Publication bias might have distorted the overall picture. However, there is no definite evidence to suggest that it has, in effect, taken place.
One of the possible strengths of photomedicines is the relative lack of ADRs (Ernst 1995). With antidepressants suicides through overdose represent a particular problem (Jick et al. 1995). There are no reports of hypericum intoxication, but the overall death rate following overdose of synthetic antidepressants has recently been reported to amount to 30.1 deaths per million prescriptions (Henry et al. 1995). It is conceivable that hypericum offers a relevant advantage over conventional antidepressants in this respect. More research is needed if this notion is to be developed into evidence.
Too good to be true?
Another relevant concern is the heterogeneity of diagnoses. According to the evidence presented here, hypericum seems to be effective for almost any type of depression. This may be correct, but to many it will sound "too good to be true." Further work needs to address this question and should attempt to determine which diagnostic entities (types of depression) are optimally amenable to treatment with hypericum and which are not.
Copyright © 1996 by Harold H. Bloomfield, M.D. and Peter McWilliams