Updated June 09, 2015.
St. John's wort is probably the first herb to reach cult status as a psychiatric medication. Recent studies suggest that it helps mild-to-moderate depression, but that it can interact with other drugs. Does this mean that telephone self-help psychotherapy and St. John's wort together may be all that it needed for some people to treat their depression? Nobody has yet made that recommendation, but people are sure to try.
St John's wort is already popular in europe as a prescription drug.
The American College of Physicians-American Society of Internal Medicine (ACP-ASIM) released guidelines for antidepressant prescriptions which state that St. John's wort may be effective against "mild" depression, at least in the short term. The ACP-ASIM team that studied the research found that across 14 trials, 62% of depression patients given St. John's wort reported improved symptoms compared with 38% taking an inactive placebo.
Because of the widespread interest in St. John's wort, the National Institutes of Health (NIH) conducted a 3-year study of the herb. The study included 336 patients with major depression of moderate severity (rather than "mild" depression), randomly assigned to an 8-week trial. One-third of patients received a uniform dose of St. John's wort, another third sertraline, a selective serotonin reuptake inhibitor (SSRI), and the final third a placebo (a pill that looks exactly like the SSRI and the St.
John's wort, but has no active ingredients). There was no significant difference in rate of response for depression, but the scale for overall functioning was better for the antidepressant than for either St. John's wort or placebo.
The Food and Drug Administration issued a Public Health Advisory on February 10, 2000. It stated that St. John's wort appears to affect an important metabolic pathway (cytochrome P450) that is used by many drugs prescribed to treat conditions such as AIDS, heart disease, depression, seizures, certain cancers, and rejection of transplants. Therefore, health care providers should alert their patients about these potential drug interactions.
But what's in those capsules you buy at the health food store? The United States does not strongly regulate nutritional supplements. While this hands-off approach may be good in allowing substances to be marketed, it makes it hard to know the potency of herbal products.
Should people take St. John's Wort? I certainly can't prescribe it. If you are mildly depressed and are not on any other medications then it may be helpful. Be careful, though. Stick to a well-known brand and notice how it affects you - and tell your doctor! If you don't feel better in 3-4 weeks, then see your doctor.
Reference:
- Annals of Internal Medicine 2000;132:743-756.
- Lancet, Vol. 355, Feb. 12, 2000
Last updated 11/8/05