Effects of a standardized extract of Withania somnifera (Ashwagandha) on depression and anxiety symptoms in persons with schizophrenia participating in a randomized, placebo-controlled clinical trial

Ann Clin Psychiatry. 2019 May;31(2):123-129.


Background: Extracts of Withania somnifera (WSE), or Ashwagandha, has traditionally been used as an adaptogen in Ayurvedic medicine, and evidence suggests that it may have efficacy in the treatment of psychiatric disorders, including schizophrenia. This secondary analysis reviewed change in depression and anxiety symptoms in a study using WSE as an adjunctive treatment in patients with schizophrenia experiencing an exacerbation of positive symptoms.

Methods: We enrolled patients with schizophrenia in a 12-week, randomized, placebo-controlled, double-blind study. Active treatment was with 1,000 mg of standardized WSE. This analysis reviewed outcomes for 66 patients with depression and anxiety symptoms by examining the singleitem depression and anxiety-depression cluster subscores extracted from the Positive and Negative Syndrome Scale.

Results: Medium effect sizes of 0.683 (95% confidence interval [CI], 0.16 to 1.21) and 0.686 (95% CI, 0.16 to 1.21) favoring WSE over placebo were observed for depression single-item and anxiety-depression cluster scores, respectively. Adverse events were mild and transient.

Conclusions: Our findings suggest that WSE may hold promise in the treatment of depression and anxiety symptoms in schizophrenia. While the mechanism of its clinical efficacy requires more exploration, the data suggest.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antipsychotic Agents* / therapeutic use
  • Anxiety* / drug therapy
  • Brief Psychiatric Rating Scale
  • Depression* / drug therapy
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Plant Extracts / administration & dosage*
  • Schizophrenia* / drug therapy
  • Treatment Outcome
  • Withania


  • Antipsychotic Agents
  • Plant Extracts
  • Ashwagandha