Kava-kava extract WS 1490 versus placebo in anxiety disorders - a randomized placebo-controlled 25-week outpatient trial
Key Finding
Kava extract produced progressively greater anxiety reductions over 25 weeks without tolerance development.
Plain-English Summary
This randomized, double-blind, placebo-controlled trial examined kava extract (WS 1490, 300mg kavalactones daily) for generalized anxiety disorder in 101 outpatients over 25 weeks - one of the longest kava trials conducted.
The kava group showed progressively greater improvements in anxiety scores compared to placebo throughout the study. Significant differences emerged from week 8 and continued to increase. By week 25, the kava group had substantially lower Hamilton Anxiety Scale scores.
Kava's kavalactones modulate GABA receptors, sodium channels, and monoamine reuptake, producing anxiolytic effects without the cognitive impairment associated with benzodiazepines. This long-term study demonstrated sustained efficacy without tolerance development. The extract was well-tolerated, though liver safety monitoring is recommended with kava use.