Preprint / Version 1

Effects of Withania somnifera (Ashwagandha) on Stress and the Stress-Related Neuropsychiatric Disorders Anxiety, Depression, and Insomnia

Authors

  • Alex Speers BENFRA Botanical Dietary Supplements Research Center, Oregon Health and Science University, Portland, Oregon, USA; 2Department of Neurology, Oregon Health and Science University, Portland, Oregon, USA; 3Helfgott Research Institute, National University of Natural Medicine, Portland, OR, USA
  • Kadine Cabey BENFRA Botanical Dietary Supplements Research Center, Oregon Health and Science University, Portland, Oregon, USA; 2Department of Neurology, Oregon Health and Science University, Portland, Oregon, USA; 3Helfgott Research Institute, National University of Natural Medicine, Portland, OR, USA
  • Amala Soumyanath BENFRA Botanical Dietary Supplements Research Center, Oregon Health and Science University, Portland, Oregon, USA; 2Department of Neurology, Oregon Health and Science University, Portland, Oregon, USA; 3Helfgott Research Institute, National University of Natural Medicine, Portland, OR, USA
  • Kirsten Wright BENFRA Botanical Dietary Supplements Research Center, Oregon Health and Science University, Portland, Oregon, USA; 2Department of Neurology, Oregon Health and Science University, Portland, Oregon, USA; 3Helfgott Research Institute, National University of Natural Medicine, Portland, OR, USA

Keywords:

Anxiety, depression, insomnia, stress, Ashwagandha, Withania somnifera

Abstract

Withania somnifera (WS), also known as Ashwagandha, is commonly used in Ayurveda and other traditional medicine systems. WS has seen an increase in worldwide usage due to its reputation as an adaptogen. This popularity has elicited increased scientific study of its biological effects, including a potential application for neuropsychiatric and neurodegenerative disorders. Objective This review aims to provide a comprehensive summary of preclinical and clinical studies examining the neuropsychiatric effects of WS, specifically its application in stress, anxiety, depression, and insomnia. Methods Reports of human trials and animal studies of WS were collected primarily from the PubMed, Scopus, and Google Scholar databases. Results WS root and leaf extracts exhibited noteworthy anti-stress and anti-anxiety activity in animal and human studies. WS also improved symptoms of depression and insomnia, though fewer studies investigated these applications. WS may alleviate these conditions predominantly through modulation of the hypothalamic-pituitary-adrenal and sympathetic-adrenal medullary axes, as well as through GABAergic and serotonergic pathways. While some studies link specific withanolide components to its neuropsychiatric benefits, there is evidence for the presence of additional yet unidentified active compounds in WS. Conclusion While benefits were seen in the reviewed studies, significant variability in the WS extracts examined prevents a consensus on the optimum WS preparation or dosage for treating neuropsychiatric conditions. WS generally appears safe for human use; however, it will be important to investigate potential herb-drug interactions involving WS if used alongside pharmaceutical interventions. Further elucidation of active compounds of WS is also needed. Keywords: Anxiety, depression, insomnia, stress, Ashwagandha, Withania somnifera

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