Evaluating Medicinal Herbs

Over the last 10 years, herbal products have moved from the dusty back shelves of rarely patronized small health food stores to prominent displays in major retail stores and pharmacies across the United States. Americans have come to accept medicinal herbs as part of the healthcare scene, and in this respect are fast catching up with their European colleagues. But do they work? Are they effective? Are they safe? How do they compare with the proven efficacy of standard treatments? Can they safely be combined with other medicines? Can they promote wellness when taken by healthy people? For example, might ginkgo help prevent age-associated memory impairment or enhance memory and performance among healthy subjects? These issues are especially important in neuropsychiatry given that anxiety, depression, and pain are among the most common reasons why consumers seek complementary and alternative treatment. Ginkgo, St. John's wort, kava, and valerian were among the top 15 herbal products sold in 1998. Much of the enthusiasm and excitement surrounding medicinal herbs has given way to a more sober appraisal of benefit-risk issues, as data are now, in some cases, showing more limited benefit or no benefit at all, as well as the possibility of potentially serious side effects. This issue of CNS Spectrums provides a welcome and much needed opportunity to review several important issues and promising leads in the application of medicinal herbs to neuropsychiatry. In this month's first article, Dr. Jerry Cott reviews the important issue of herb-drug interactions. Dr. Cott discusses the main types of kinetic interactions that can occur and reviews data pertaining to specific psychotherapeutic herbdrug interactions, including those with St. John's wort. Dr. Cott's article is followed by Dr. Samantha MeltzerBrody's review of the clinical efficacy of St. John's wort. St. John's wort has been an established treatment in medicinal herbalism for centuries. In the last decade, the herb has gained great popularity among consumers as an alternative and generally self-administered treatment for depression. Dr. Meltzer-Brody describes the herb's chemical constituents and purported mechanisms of action, and reviews studies of its use in depression, its adverse-effect profile, and other potential clinical applications in psychiatry. Dr. Andrew Krystal and liana Ressler review what is known about valerian, an herb widely used in Europe for its soporific effects. Despite its previous popularity, especially among combatants of World Wars I and II, less is known about valerian than of the some other central nervous system-active botanicals. Moreover, in recent years it has received comparatively little attention in the United States. The evidence presented suggests some promise for the compound, along with a rather unique action profile given its indication for sleep disturbance. This month's final two articles describe original research using kava, a traditional anxiolytic substance from the South Pacific islands. For over a decade, kava has been widely used for anxiety, stress, and insomnia in central Europe. Dr. Kathryn Connor and colleagues provide data on kava's safety profile, including its tolerability and withdrawal effects from a short-term, double-blind, placebo-controlled trial in generalized anxiety disorder. If kava proves to be as safe and well-tolerated as the data suggest, and if its efficacy is equivalent to standard treatments, the herb could become an important option in managing anxiety. Finally, Dr. Stewart Barnett and colleagues describe the development and validation of a self-rating instrument—the Self-Assessment of Resilience and Anxiety scale—designed to have special applicability for the study of kava, based upon reported actions of the herb. The scale, which rates not only anxiety, but feelings of confidence and resilience as well, might have wider applications (ie, in milder but clinically meaningful anxiety states), however, and is not intended to be limited to the assessment of kava's effects. As guest editors of this issue, we express appreciation for the opportunity to address this particular topic, which continues to become an increasingly important health issue around the world. We thank Dr. Jack Gorman, editor of CNS Spectrums, and Ms. Lisa Arrington, acquisitions editor, for their support, and we hope that the reviews and original research presented herein will enhance our understanding of herbal remedies in neuropsychiatry. KSfiEl