Hypericum extract is at least as effective as imipramine in the treatment of moderate depression, say German researchers.
Hypericum was given as a dose of 350mg three times a day (total daily dose equivalent to 6g crude herb) in a trial which compared its efficacy with imipramine 100mg daily (after titration) and placebo. The randomised, double blind trial used a depression rating scale to assess the effectiveness of each treatment. One hundred patients were given hypericum extract, 105 imipramine and 46 placebo.
Professor Michael Philipp (professor of psychiatry, Bezirkskrankenhaus Landshut, Germany) and colleagues report that, after six weeks of treatment, hypericum was determined to be more effective than placebo in the treatment of moderate depression. In addition, equivalent efficacy was shown between hypericum and imipramine.
In terms of safety, 22 per cent of the hypericum group, 46 per cent of the imipramine and 19 per cent of the placebo group reported adverse effects - none serious. The most reported side effect for hypericum was nausea, followed by dry mouth. Other adverse effects included constipation, palpitation, headache and dizziness.
The authors comment that hypericum products may vary considerably in composition, so their results cannot be generalised to other extracts. However, they conclude that hypericum extract may be considered as an "alternative first choice treatment in most cases of mild-to-moderate depression without psychotic symptoms" (British Medical Journal 1999;319:1534).
An opposing view of the safety of hypericum has been reported in the Lancet (1999;354:2014). While there are few doubts about its efficacy, its safety has recently been questioned, says Professor Edzard Ernst (department of complementary medicine, University of Exeter). He says that at least eight cases have been reported of hypericum interacting with other medication, which suggest that hypericum extracts are "potent inducers of hepatic enzymes". The interactions were with theophylline, cyclosporin, warfarin and a combined oral contraceptive. He comments that it is a misconception that "natural always equates with harmless".