A double-blind randomised trial to investigate three different concentrations of a standardised fresh plant extract obtained from the shoot tips of Hypericum perforatum L.

The aim of this randomised double-blind multi-centre parallel group comparative study was to investigate the efficacy and tolerability of a new standardised fresh-plant extract obtained from the shoot tips of St. John's wort (Hypericum perforatum L.) in the treatment of mild to moderate depression. 348 outpatients (259 female, 89 male) with mild to moderate depression were recruted by 12 psychiatric specialty practices and 26 general practices. The patients took during 6 weeks 3 times a day 1 tablet of a Hypericum preparation standardised to either 0.17 mg (114 patients), 0.33 mg (115 patients), or 1 mg (119 patients) total hypericin per day (Hyperiforce**). The main outcome measure was the Hamilton Psychiatric Rating Scale for Depression; additional measures were the Hospital Anxiety and Depression Scale and the Clinical Global Impression. At the end of treatment, a reduction in the average Hamilton Depression score from an initial 16-17 to 8-9, i.e. a relative reduction of about 50%, was observed in all groups (280 patients, par protocol analysis). The response rates were 62%, 65% and 68%, respectively (348 patients, intention to treat analysis). Overall, the intergroup comparison revealed no significant differences. Tolerability was excellent, with mild adverse reactions probably causally related to the treatment occurring in only 7 of the 348 patients (2%). This Hypericum preparation is effective in all three doses and is well tolerated.