One hundred and five outpatients with mild depressions of short duration were treated in a double-blind study with either 3 x 300 mg hypericum extract or placebo. The therapy phase was 4 weeks. The effectiveness was judged according to the Hamilton Depression Scale after 2 and 4 weeks. The values of the mean basic score in these periods fell from 15.8 to 9.6 or 7.2 in the active group, and in the placebo group, from 15.8 to 12.3 and 11.3. The differences between active and placebo groups were statistically significant with P < .05 and P < .01 achieved after 2 and 4 weeks, respectively. In the active group, 28 of 42 patients (67%) and, in the placebo group, 13 of 47 patients (28%) responded to treatment. Notable side effects were not found.