The amygdalae are small, bilateral regions in the brain considered part of the limbic system. As such, they are important in the processing and regulation of memory and emotions, especially fear and anxiety. Dysfunction or imbalance within the amygdala often results in maladaptive social behavior, such as phobias, compulsions, paranoia and depression. Some herbs affect brain chemistry and hormone production, which can balance amygdala function and alleviate symptoms. Consult with your doctor before mixing herbal supplements with any prescription drugs.
The amygdala region consists of almond-shaped groups of neurons closely clustered together within the medial temporal lobes of your brain. It performs a primary role in the formation and storage of memories associated with strong emotional events, especially those involving fear and anxiety, according to the book "Human Physiology: An Integrated Approach." The amygdala is also involved in memory consolidation, which is transferring memories from short-term storage into long-term storage between different parts of the brain. Brain chemicals, called neurotransmitters, and hormones, especially those produced by the adrenal glands, are closely associated with amygdala function.
Kava kava, also called Piper methysticum, is a shrub and member of the pepper family that is indigenous to the South Pacific islands. Kava kava has a long history as an herbal medicine, especially for the treatment of anxiety, depression, insomnia and mild pain. According to the "Natural Standard Herb & Supplement Reference: Evidence-based Clinical Reviews," limited research indicates that Kava kava may reduce over-activity within the amygdala region and limbic system in general, which is the part of your brain associated with anxiety disorders. Kava kava is not addictive and it's been approved for use with insomnia and anxiety in Germany and Switzerland.
St. John's Wort
St. John's wort is a plant with yellow flowers used to prepare teas, extracts and tablets for the relief of depression, anxiety and sleep disorders. It works primarily by increasing levels of serotonin in your brain. According to a Pakistani study on rats published in a 2009 edition of the "Pakistan Journal of Pharmaceutical Sciences," St. John's wort has a significant affect on hormones and neurotransmitters related to stress, and reduces the impact of stress on the amygdala and other structures in the brain.
Cortisol Regulating Herbs
Cortisol and adrenaline are produced by your adrenal glands, which sit atop your kidneys, in response to stress. Both hormones quickly reach your brain and activate the amygdala, which causes more cortisol to be produced if the stress, fear, anxiety or other negative emotions are not resolved. As such, controlling cortisol release from the adrenal glands reduces over-activity within the amygdala and the establishment of a positive feedback loop. Herbs classified as adaptogens have the ability to lower hormones when they are high, but increase them when they are too low. According to "Principles and Practice of Phytotherapy: Modern Herbal Medicine," adaptogenic herbs that can help to moderate activity in the amygdala and reduce symptoms of anxiety and depression include rhodiola, Siberian ginseng, licorice and valerian root.