По зверобою есть доказательные исследования

J Geriatr Psychiatry Neurol. 1994 Oct;7 Suppl 1:S9-11.

Placebo-controlled double-blind study examining the effectiveness of an hypericum preparation in 105 mildly depressed patients.
Sommer H, Harrer G.
Psychiatrische Fachpraxis, Universität Salzburg, Austria.

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.

PMID: 7857516 [PubMed - indexed for MEDLINE
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J Geriatr Psychiatry Neurol. 1994 Oct;7 Suppl 1:S15-8.
Multicenter double-blind study examining the antidepressant effectiveness of the hypericum extract LI 160.
Hänsgen KD, Vesper J, Ploch M.
Institut für Psychologie, Universität Fribourg/Schweiz, Germany.

Seventy-two depressive patients of 11 physicians' practices were treated in a double-blind study for a period of 6 weeks either with hypericum extract LI 160 or with placebo. Inclusion criterion was a major depression in accordance with DSM-III-R. The changes were assessed using four psychometric scales (HAMD, D-S, BEB, CGI). After 4 weeks of therapy, the statistical evaluation revealed a significant improvement in all four psychometric tests in the active group as compared to the placebo group. After switching the placebo group to active treatment (5th to 6th week of therapy), significant improvements were found in the original placebo group. No serious side effects were observed.

PMID: 7857501 [PubMed - indexed for MEDLINE]
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BMJ. 2000 September 2; 321(7260): 536–539.

Comparison of St John's wort and imipramine for treating depression: randomised controlled trial

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