Many Herbal Supplements As Good or Better Than Antidepressants

A new scoping review found that many herbal supplements are as good as prescription drugs at treating depression. The study—including 209 trials of various products—found that St. John’s Wort was at least as good as antidepressants (beating them in some studies). Other supplements like probiotics, saffron, and vitamin D beat placebo more consistently than antidepressant drugs.

St. John’s Wort directly beat antidepressants in four studies and had the same efficacy as the drugs in 11 studies. Only one study found it to be worse than antidepressants.

Compared to placebo, antidepressant drugs (which beat placebo in 51% all clinical trials) are less consistently effective than saffron (beating placebo in 73% of trials), vitamin D (beating placebo in 67% of trials), St. John’s Wort (beating placebo in 64% of trials), and probiotics (beating placebo in 60% of trials).

Some supplements fare worse, however. Omega-3s only beat placebo in 36% of trials, making them a worse option.

Other supplements had “promising” results in the current review, but these came from just a handful of small studies with variable doses and preparations. Thus, these products certainly require more research before researchers can say they are effective. These include folic acid, lavender, zinc, tryptophan, rhodiola, and lemon balm.

Some supplements, like melatonin and magnesium, showed mixed results even in the few, small studies in which they were evaluated, making them less promising.

The study, published in Frontiers in Pharmacology, was led by Rachael Frost at Liverpool John Moores University and University College London.

Although psychiatrists often warn patients about St. John’s Wort since it can interact with other drugs and cause serotonin syndrome, this is also true of prescription antidepressants. A review from 2016 found that antidepressants caused significantly more adverse effects and more people dropped out of the antidepressant drug trials due to drug harms. That review concluded that “St John’s wort extract is safer than SSRIs.”

In the current study, 69% of the trials reported data on adverse effects; 85% of those found no significant harms compared to placebo. In the few cases of increased side effects, they were considered mild.

“A substantial number of trials did not report sufficient safety data, particularly for dietary supplements. However, in those that did, most products had a good safety profile,” the researchers write.