Clinical efficacy of kava extract WS 1490 in sleep disturbances associated with anxiety disorders. Results of a multicenter, randomized, placebo-controlled, double-blind clinical trial.

Background: The aim of the present trial was to investigate the efficacy and safety of kava special extract WS 1490 in patients with sleep disturbances associated with anxiety, tension and restlessness states of non-psychotic origin.

Methods: In a multicenter, randomized, double-blind clinical study, 61 patients received daily doses of 200 mg WS 1490 or placebo over a period of 4 weeks. Efficacy was measured by the sleep questionnaire SF-B, the Hamilton Anxiety Scale (HAMA), the Bf-S self-rating scale of well-being and the Clinical Global Impressions (CGI) scale.

Results: The confirmatory analysis of the two primary efficacy variables, the differences of sleep questionnaire SF-B sub-scores 'Quality of sleep' and 'Recuperative effect after sleep' after 4 weeks of double-blind treatment compared to baseline, demonstrated statistically significant group differences in favor of kava extract WS 1490 (P=0.007 and P=0.018, respectively). Superior effects of kava extract were also present in the HAMA psychic anxiety sub-score (P=0.002). More pronounced effects with respect to the self-rating of well-being and the global clinical evaluation also indicated superior therapeutic efficacy of kava extract. Safety and tolerability were good, with no drug-related adverse events or changes in clinical or laboratory parameters.

Conclusions: We conclude that sleep disturbances associated with non-psychotic anxiety disorders can be effectively and safely treated with kava extract WS 1490.