Herbal remedies and nutraceuticals as augmentation or adjunct for mood and anxiety disorders: Evidence for benefit and risk

Abstract

Complementary and alternative medicine (CAM) therapies have considerable patient appeal. Perceived as better, safer and more economical than conventional treatments, such as pharmacotherapy and psychotherapy, they are often used by patients to self-treat symptoms of depression and anxiety, usually in combination with existing medications and without medical supervision. CAM therapies include physical therapies (e.g. exercise), herbal remedies (e.g. St. John's wort) and nutraceuticals/dietary supplements (e.g. omega-3 fatty acids). This chapter will review the published evidence for the use of herbal and dietary supplements as augmenting or adjunctive agents in depressive and anxiety disorders Methods: A PubMed search was conducted for all randomized controlled trials, open trials and case reports available and published up to May 2012 on the use of herbal remedies and dietary supplements, as augmentation or combination, particularly to medications, in the treatment of unipolar depression, bipolar disorder and anxiety conditions.Results: Overall, the published literature is sparse. Among available data in depressive disorders, there is a moderate level of evidence to support adjunctive use of Free and Easy Wanderer Plus (FEWP) and folate in unipolar depression, and FEWP and omega-3 fatty acids in bipolar depression. Several other herbal remedies and nutraceuticals have preliminary evidence of benefit as augmentation to pharmacotherapy, including S-adenosylmethionine (SAM-e), dehydroepiandrosterone (DHEA), folate, and zinc, in unipolar depression; magnesium in mania; N-acetylcysteine (NAC) in bipolar depression; and E. M. Power Plus (EMP+) in bipolar disorder. Surprisingly, there is no published evidence to support the benefit of St. John's wort as adjunct to antidepressants. Similarly, evidence of benefits for other herbal and dietary supplements remains limited. In anxiety disorders, there is, as yet, little evidence that herbal and dietary supplements are useful as augmenting agents.Limitations: The overall evidence base remains limited and studies often had methodological problems, including small samples, variability in dose, short duration of treatment, and unknown quality of the agent. Though the supplements were generally well tolerated in reported studies, there is limited long-term safety and tolerability data, and drug-drug interaction information.Conclusions: While several herbal and dietary supplements have evidence of benefit as add-on agents in depressive disorders, none can currently be recommended for anxiety conditions, and safety issues should be carefully considered prior to use in clinical practice. Larger well-designed studies are needed to provide a broad and reliable base of data for further evaluations.