Date of Award


Degree Type

Selective Evidence-Based Medicine Review

Degree Name

Master of Science in Health Sciences - Physician Assistant


Physician Assistant Studies

Department Chair

John Cavanagh, PhD, PA-C


OBJECTIVE: The objective of this systematic review is to determine is Kava (piper methysticum) safe and effective for reducing anxiety in adult patients 18-65?

STUDY DESIGN: Review of three English language primary randomized controlled studies published from 2005-2009.

DATA SOURCES: Randomized, double blind, placebo-controlled trials comparing Kava and placebo were found using OVID, PubMed, and CINAHL and COCHRANE databases.

OUTCOMES MEASURED: Each of the three trials assessed the adverse event of hepatotoxicity and clinical improvement in anxiety symptoms. Studies utilized to measure change in anxiety symptoms included State Trait Anxiety Inventory (STAI-state), Hamilton Anxiety Scale (HAMA), the Hospital Anxiety and Depression Scale (HADS), Sheehan Disability Inventory (SDI), and Beck Depression Inventory-II (BDI-II).

RESULTS: Three double-blind randomized controlled trials were included in this review. Results from the Conner et al study indicate that Kava use is effective in reducing anxiety in individuals with low baseline anxiety, but there were no differences between Kava and placebo when HAMA scores were > 16 or > 18. The second study by Sarris et al concluded that the response rate after treatment with Kava was 62% with a remission rate of 35%. The third study by Jacobs et al showed a reduction in anxiety symtpoms, but not greater than that of placebo; however, the data was not statistically significant. All three trials demonstrated that kava use does not contribute to hepatotoxicity.

CONCLUSIONS: All of the RCTs demonstrate that Kava use is safe and effective at reducing anxiety. However, it seems to be a less efficient option in the overall anxiety score reduction when compared to the current available treatment. In addition, the studies failed to demonstrate that Kava has an effect on hepatotoxicity.