A Standardized Withania somniferra (Linn.) Root Extract with Piperine Alleviates the Symptoms of Anxiety and Depression by Increasing Serotonin Levels: A Double-Blind, Randomized, Placebo-Controlled Study.

Background: Withania somnifera (Linn) or Ashwagandha is used in Ayurveda and other traditional medicine systems as an adaptogen and a neuroprotective supplement. Objective: The effect of Ashwagandha root extract (ARE) standardized for 2.5% full-spectrum withanolides as per The United States Pharmacopeia (USP) protocol with piperine (500 mg with 5 mg of 95% piperine) once a day (12.5 mg withanolides/day) was evaluated in individuals with mild to moderate depression and anxiety. Methods: In a randomized, double-blind placebo-controlled study, for 90 days, 70 participants were randomized to ARE ( n  = 34) or placebo ( n  = 36) once daily at night. Mean change in the Hamilton Depression Rating Scale (HDRS) and Hamilton Anxiety Rating Scale (HARS), Groningen Sleep Quality Scale (GSQS), and quality of life (QOL) from screening to days 30, 60, and 90 were evaluated. Safety was evaluated by monitoring any incidence of adverse events and laboratory parameters. Two-way analysis of variance (ANOVA) and repeated-measure ANOVA were used to compare ARE and placebo, and the changes within the group at different time points. Results: Seventy individuals were randomized and all of them completed the study. The HARS, HDRS, GSQS, and QOL scores improved significantly ( p  < 0.001) in all the participants taking ARE compared to placebo on days 30, 60, and 90. Anxiety and depression improved from baseline to end of the study in both groups, but the quantum of improvement was significantly higher in ARE. Serum levels of serotonin increased in ARE, but showed a decrease in placebo, the difference being statically significant ( p  < 0.001). Biochemical and hematological parameters remained in the normal range in all participants and ARE was well tolerated during the study. Conclusion: The results of the study suggest that 500 mg of ARE standardized for 2.5% withanolides with 5 mg piperine is beneficial in improving depression, and anxiety, by increasing serum serotonin levels. The trial was registered prospectively with the Clinical Trial Registry of India (CTRI) with the registration number CTRI/2022/05/042640, on May 18, 2022.