1.53 times as many responded as on placebo, in mild to moderate cases
Pooled across 18 trials in 2,922 people with mild or moderate major depression. That band is the only one where the question has been properly asked.
What the study found
Half again as many responders as placebo, in mild to moderate cases
The effect is real and it is bounded. Pooled across 18 trials in 2,922 people with mild or moderate major depression, 1.53 times as many responded to St John's Wort as to placebo. That band is the only one where the question has been properly asked.
The caveat · The pooled trials disagree widely
The trials disagree with each other far more than a pooled number suggests, with heterogeneity running to 89 percent, and the reviewers downgraded every headline estimate because of it. Smaller trials reported roughly double the benefit of larger ones. Trials from German-speaking countries, where the extracts are manufactured, reported results more favourable than trials from elsewhere.