We're building a better ClinicalTrials.gov. Check it out and tell us what you think!
ClinicalTrials.gov Menu

Kava for the Treatment of Generalised Anxiety Disorder: A Double-Blind Randomised Placebo-Controlled Trial (KGAD)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT02219880
Recruitment Status : Completed
First Posted : August 19, 2014
Last Update Posted : October 15, 2018
Swinburne University of Technology
The University of Queensland
Information provided by (Responsible Party):
Jerome Sarris, University of Melbourne

Brief Summary:
The use of Kava in Generalised Anxiety Disorder: an 18-week double-blind, randomised, placebo-controlled study.

Condition or disease Intervention/treatment Phase
Generalized Anxiety Disorder Dietary Supplement: Kava (240mg of kavalactones per day) Dietary Supplement: Placebo Phase 4

Detailed Description:

The primary aim is to confirm the efficacy and safety of Kava compared to placebo in Generalized Anxiety Disorder (GAD). Secondary aims of the study are to confirm the relationship between specific genetic variations and response to Kava, and to explore the effects of Kava on the expression of specific genes.

Consenting participants will be randomly allocated to take either Kava or placebo over 18 weeks. They will be assessed at regular interviews throughout the trial and will have four blood tests (liver function tests to monitor participant safety, and collection of genetic material providing information on neurochemistry). The design of the study is a multi-centre, 18-week, 2-arm, double-blind randomised clinical trial (RCT) using a standardised pharmaceutical-grade water-soluble extract of Kava (240mg of kavalactones per day) versus placebo in 210 adults with GAD.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 178 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary Purpose: Treatment
Official Title: Kava for the Treatment of Generalised Anxiety Disorder: A Double-Blind Randomised Placebo-Controlled Trial
Actual Study Start Date : October 13, 2015
Actual Primary Completion Date : May 31, 2018
Actual Study Completion Date : May 31, 2018

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Anxiety

Arm Intervention/treatment
Placebo Comparator: Placebo
Inert tablets matched for colour, size and consistency to active arm treatment. Both treatment arm tablets will match in appearance, and neither participants nor the trial clinicians will know what they are taking.
Dietary Supplement: Placebo
Inert tablets containing vegetable fibre matched for colour, size and consistency to active arm treatment.

Experimental: Kava - standardised 240mg kavalactones
Standardised 240mg kavalactones per day - fixed dose regime of two tablets of kava twice per day
Dietary Supplement: Kava (240mg of kavalactones per day)
Kava 60 milligrams per tablet = 240mg of kavalactones per day
Other Names:
  • Kava
  • Kavalactones
  • Piper methysticum

Primary Outcome Measures :
  1. Hamilton Anxiety Rating Scale (HAMA) - change in score [ Time Frame: 18 weeks ]
    Reduction of participant's anxiety will be assessed on the HAMA from baseline to week 16 across time used a mixed methods model.

Secondary Outcome Measures :
  1. Gamma-aminobutyric acid (GABA) transporter polymorphisms moderating response to study intervention [ Time Frame: 18 weeks ]
    Will assess whether response to Kava will be moderated by gamma-aminobutyric acid (GABA) transporter polymorphisms. Specifically, whether rs2601126-T allele or rs2697153-A allele carriers have greater reduction of anxiety

Other Outcome Measures:
  1. Changes in score to psychometric questionnaire measures [ Time Frame: 18 weeks ]
    Depressive symptoms on the Montgomery-Asberg Depression Rating Scale (MADRS), self-rated anxiety on the Beck Anxiety Inventory (BAI), pathological worry on the Penn State Worry Questionnaire (PSWQ), and health-related quality of life on the Short Form Survey-12 (SF-12) will also be significantly improved by Kava over placebo; and

  2. Monoamine and GABA differential gene expression [ Time Frame: 8 weeks ]
    Differential gene expression will be assessed from baseline to week 8 from participants in the Melbourne site. This will determine whether Kava increases expression of genes effecting expression of neurochemical e.g. GABA, and monoamines

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years to 70 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

To be considered for inclusion in this study, participants will be required to meet the following criteria:

  • Aged between 18-70 years
  • Meets the Diagnostic and Statistical Manual (DSM) IV and DSM-V diagnostic criteria for generalised anxiety disorder (GAD) based on structured interview (Mini International Neuropsychiatric Interview-Plus 6 [MINI-Plus 6]. Note that while the MINI-Plus 6 uses the DSM-IV criteria, the same criteria are used in the DSM-V).
  • Presents with anxiety (Hamilton Anxiety Rating Scale ≥ 18) at the time of study entry
  • Fluent in written and spoken English
  • Provides a signed copy of the consent form

Participants are ineligible to enter the trial if they have any of the following conditions:

  • Primary diagnosis other than GAD
  • Presentation of moderate to severe depressive symptoms (Montgomery-Asberg Rating Scale: MADRS ≥ 18 at time of study entry or ≥ 24 at any time during study)
  • Presentation of suicidal ideation (≥ 3 on MADRS suicidal thoughts domain at time of study entry or at any time during study)
  • Current diagnosis of bipolar disorder or schizophrenia on structured interview (MINI Plus)
  • Current substance/alcohol use disorder on structured interview (MINI Plus) Page 21 of 39 Commercial-in-Confidence
  • Currently taking an antidepressant, mood stabiliser, antipsychotic, anticonvulsant, warfarin or thyroxin, or current regular use (more than 2 days per week) of a benzodiazepine or opioid-based analgesic
  • Current use of a psychotropic nutraceutical (e.g. St John's wort)
  • Previous intolerance to kava
  • Three or more failed trials of pharmacotherapy for the current GAD episode
  • Recently commenced psychotherapy (within four weeks of study entry)
  • Known or suspected clinically unstable systemic medical disorder
  • Diagnosed hepato-biliary disease/inflammation
  • Elevated liver enzymes at baseline blood test
  • Pregnancy or breastfeeding, or trying to conceive
  • Not using medically approved contraception (including abstinence) if female and of childbearing age
  • Unable to participate in all scheduled visits, treatment plan, or other trial procedures according to the protocol (except for the optional genetic component)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02219880

Layout table for location information
Australia, Queensland
Royal Brisbane & Women's Hospital
Brisbane, Queensland, Australia, 4006
Australia, Victoria
Centre for Human Psychopharmacology - Swinburne University
Melbourne, Victoria, Australia, 3122
Sponsors and Collaborators
University of Melbourne
Swinburne University of Technology
The University of Queensland
Layout table for investigator information
Principal Investigator: Jerome Sarris, PhD The University of Melbourne and The Melbourne Clinic
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Layout table for additonal information
Responsible Party: Jerome Sarris, Dr Jerome Sarris, University of Melbourne
ClinicalTrials.gov Identifier: NCT02219880    
Other Study ID Numbers: 137/14
First Posted: August 19, 2014    Key Record Dates
Last Update Posted: October 15, 2018
Last Verified: October 2018
Keywords provided by Jerome Sarris, University of Melbourne:
Generalized Anxiety Disorder
Additional relevant MeSH terms:
Layout table for MeSH terms
Anxiety Disorders
Pathologic Processes
Mental Disorders