Chapter 21: Over-the-Counter Dietary Supplements and Herbal Products

The material addresses why patients increasingly seek complementary and alternative medicine approaches, particularly for mood disorders, anxiety, sleep disturbances, and cognitive concerns. The chapter reviews evidence-based research on commonly used supplements including St. John's Wort for depression, omega-3 fatty acids for mood stabilization, melatonin for sleep regulation, and other botanicals like ginkgo biloba and valerian root, while critically examining their mechanisms of action and demonstrated clinical outcomes. A significant portion focuses on regulatory challenges inherent to the dietary supplement industry, including inadequate standardization, inconsistent quality control, variable potency across manufacturers, and limited oversight by regulatory agencies compared to pharmaceutical medications. The chapter identifies specific supplements associated with serious safety concerns, such as kava kava's hepatotoxic potential and yohimbine's anxiogenic properties, emphasizing the risks of adverse effects. Equally important is the discussion of dangerous pharmacokinetic and pharmacodynamic interactions between herbal products and psychiatric medications, particularly with antidepressants, benzodiazepines, and mood stabilizers, where supplements may reduce therapeutic efficacy or precipitate toxicity. The material also addresses emerging pharmacological interventions like ketamine and its mechanism through NMDA receptor antagonism in treatment-resistant depression, representing the intersection of novel psychiatric treatments and evolving clinical practice. Throughout, the chapter emphasizes the necessity for clinicians to maintain awareness of patient supplement use, conduct thorough medication histories that include over-the-counter and herbal products, and educate patients about evidence-based efficacy and potential risks associated with unregulated products.