Kava (a.k.a. kava kava) is an herb that has been used to treat a variety of anxiety disorders. It is rated as "likely effective," for this use based upon review of scientific literature. In some studies, kava was found to possibly be as effective as low dose benzodiazepines (BDZ), a class of pharmacological agents commonly used for anxiety.
Kava kava for anxiety
- In general kava is considered to be superior to placebo in the treatment of anxiety. However, most studies conducted are based on an extract of kava containing 70% kava-lactones (kavapyrones). Dried kava herb contains approximately 3.5% of kava-lactones.
- Treatment for 1 to 8 weeks may be necessary to achieve a therapeutic effect.
Why It May Work
Kava contains kava-lactones that confer various pharmacological effects. The exact mechanism of action is unknown but there are a few theories as to how kava may work. One proposed mechanism is that kava increases the number of binding sites on the GABA receptor, an important component of the nervous system involved in nervous system depression.
Another theory is that kava may decrease the reuptake of norepinephrine. Kava may also work on dopamine or the limbic system as people who take it often report feeling more sociable and tranquil. Kava does not seem to work on BDZ receptors.
Although effective, using kava may pose a grave risk. In medically monitored situations kava has been used safely for up to 6 months, however, the herb has been banned in Switzerland, Germany, and Canada due to liver damage. There have been at least 68 cases of reported hepatotoxicity from kava use even with short term use at regular doses. Treatment lasting just 1 to 3 months has resulted in liver failure and even death.
People should not use kava if pregnant or lactating. If taken, usage should be supervised by a medical professional and liver function tests must be regularly performed to monitor for liver damage.
Kava can cause a variety of side effects such as dizziness, drowsiness, headache, upset stomach, dry mouth, and allergic reactions. It can also interfere with many drugs and herbs. Concomitant use of other central nervous system depressing drugs or herbs such as BDZ, barbiturates, alcohol, valerian, hops should be avoided.
photo by Forest and Kim Starr