Objective: We conducted a randomized, double-blind, placebo-controlled, parallel group trial of the efficacy and tolerability of Cimicifuga racemosa (black cohosh) extract for the treatment of anxiety disorder due to menopause. We hypothesized that black cohosh would be superior to placebo in reducing anxiety symptoms of menopause, with a comparable tolerability profile to placebo.
Materials and methods: Subjects were randomized to therapy with either pharmaceutical-grade black cohosh extract (n = 15) or placebo (n = 13) for up to 12 weeks. The primary outcome measure was changed over time in total Hamilton Anxiety Rating Scale (HAM-A) scores. Secondary outcomes included a change in scores on the Beck Anxiety Inventory, Green Climacteric Scale (GCS), and Psychological General Well-Being Index (PGWBI) and the proportion of patients with a change of 50% or higher in baseline HAM-A scores.
Results: There was neither a significant group difference in change over time in total HAM-A scores (P = 0.294) nor a group difference in the proportion of subjects with a reduction of 50% or higher in baseline HAM-A scores at study end point (P = 0.79). There was a significantly greater reduction in the total GCS scores during placebo (vs black cohosh; P = 0.035) but no group difference in change over time in the GCS subscale scores or in the PGWBI (P = 0.140). One subject (3.6%) taking black cohosh discontinued treatment because of adverse events.
Conclusions: We found no statistically significant anxiolytic effect of black cohosh (vs placebo). However, small sample size, choice of black cohosh preparation, and dosage used may have been limiting factors producing negative results.
Trial registration: ClinicalTrials.gov NCT00120458.