A guideline backs it on its own only in mild to moderate depression
Canada's depression guideline puts it at first or second line when major depression is mild to moderate, and only as a second-line addition when it is moderate to severe.
What the study found
A national guideline puts it first line, but only for milder cases
Canada's depression guideline recommends St John's Wort on its own at first or second line when major depression is mild to moderate. Where it is moderate to severe, the same guideline recommends it only as a second-line addition alongside conventional treatment, never instead of it.
The caveat · Expert consensus, evidence to 2016
A guideline is an expert reading of the evidence with consensus in the loop, not a fresh analysis, and this one closes its evidence base in 2016. Its own authors name thin drug-interaction data as a caveat across the whole complementary-medicine section.