Monica Vermani, Hon.BSc, MA Stress, Trauma, Anxiety, Rehabilitation Treatment (S.T.A.R.T.) Clinic for Mood & Anxiety Disorders, Toronto, Canada; Adler School of Professional Psychology, Chicago, Ill
Irena Milosevic, Hon.BSc University of Toronto, Toronto, Canada
Fraser Smith, BA, ND Canadian College of Naturopathic Medicine, Toronto, Canada
Martin A. Katzman, BSc, MD, FRCPC Stress, Trauma, Anxiety, Rehabilitation Treatment (S.T.A.R.T.) Clinic for Mood & Anxiety Disorders, Toronto, Canada; Department of Psychiatry, Faculty of Medicine, University of Toronto
Some herbs do work as claimed; all have the potential for downside activity as well
Many of your patients may be self-treating with herbal preparations. Ask candidly about this possibility, and become familiar with the increasing evidence on efficacy and safety of alternative treatments
A large meta-analysis and a Cochrane Review both suggest St. John’s Wort (A) is as effective as conventional antidepressants and more effective than placebo for mild to moderate depression. With patients taking St. John’s Wort and a conventional antidepressant, remain alert for a potentiating effect, “serotonin syndrome.” Use with caution if the patient must also receive anticoagulants, oral contraceptives, or antiviral agents.
The efficacy and safety of ginseng (B, in terms of psychological well-being) and evening primrose (C) for depression are not well established.
Kava-kava (A, for short-term treatment for anxiety treatment) has well-known anxiolytic properties, but its potential adverse effects, particularly liver toxicity, dramatically reduce its usefulness. Valerian, though commonly used for anxiety (C, for insomnia and anxiety), is not well supported by good data.
Ginkgo has shown promise in improving cognitive function in dementia, and its side effects are few and uncommon (A, for cognitive function in dementia). Monitor carefully if there is concomitant anticoagulant therapy.
Based on epidemiologic estimates, it may be that 20% to 30% of your patient population is using alternative/complementary medicines.1 Twenty percent of adults who take prescription medicine also rely on herbal products,2 and patients who use herbal products the most are those with chronic conditions.3
Included in this group are persons with mental health problems, who, compared with the general population, report a much greater use of alternative treatments, including herbal and homeopathic remedies.4 These remedies, when used to treat psychiatric symptoms, may produce changes in mood, thinking, or behavior, and they may interact with a number of conventional medications.3
Largely uncharted territory. With the exception of St. John’s Wort for depression and ginkgo for dementia, minimal evidence is currently available to recommend the use of herbal medicines as the primary treatment for mental illness. Although some herbs have been found to be effective at specific doses for specific conditions, there is no evidence to show their superiority to conventional drug treatments, nor has their safety been established for use during pregnancy and lactation.8
FAST TRACK
St. John’s Wort was superior to placebo and comparable with conventional antidepressants
Helping patients navigate. Nevertheless, our patients are increasingly turning to alternative therapies, and it is therefore critical that we clinicians avail ourselves of current knowledge and that investigators pursue intensive clinical research to establish safety (TABLE 1) and efficacy. Additionally, greater understanding of the biochemical and pharmacological effects of these herbs may uncover novel treatments or yield fresh insights into basic disease mechanisms.9
The herbal remedies discussed in this article are those commonly used for psychiatric conditions. Their effectiveness and potential for adverse side effects and interactions are assessed.
Depression
St. John’s Wort
St. John’s Wort (Hypericum perforatum L) is a popular herbal treatment readily used by the public in various forms, such as tablets and teas. Efficacy of hypericum—one of the hypothesized active ingredients in St. John’s Wort—in the treatment of depression was reported in the texts of the ancient Greek physicians Hippocrates, Pliny, and Galen, and it continued to be cited throughout the Classical, Renaissance, and Victorian eras. Its contemporary usage as an antidepressant has been supported by more rigorous evidence than any other herbal remedy.9
Efficacy. Evidence of efficacy in mild to moderate depression has been reported in a meta-analysis of 23 randomized trials with a total of 1757 outpatients, in which extracts of St. John’s Wort alone (20 of 23 trials) or in combination with other herbs (3 of 23) were tested against placebo (15 trials) or antidepressant drugs (8 trials).10 St. John’s Wort was reported to be clearly superior to placebo and comparable with conventional drug treatment, with lower side-effect and dropout rates. Similarly, a recent Cochrane Review of 27 trials and 2291 patients concluded that St. John’s Wort was more effective than placebo in treating mild to moderately severe depression; however, there was inadequate evidence to determine whether the herb was as effective as traditional antidepressants.11
The superiority of hypericum to placebo has been called into question, however, by a large-scale, multicenter, double-blind case report tabulation. The study, conducted with 200 patients across 11 academic medical centers in the United States, found no evidence that St. John’s Wort was more efficacious than placebo.12 Another such trial also concluded that St. John’s Wort was not an effective treatment for major depression. In addition, the herb was found to be no different than sertraline, which was also indistinguishable from the placebo, further confusing the issue.13 Strength of recommendation (SOR) is level A for the evidence in support of St. John’s Wort as an antidepressant.
