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

October 10, 2018 updated by: Jerome Sarris, University of Melbourne
The use of Kava in Generalised Anxiety Disorder: an 18-week double-blind, randomised, placebo-controlled study.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment (Actual)

178

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Australia
    • Queensland
      • Brisbane, Queensland, Australia, 4006
        • Royal Brisbane & Women's Hospital
    • Victoria
      • Melbourne, Victoria, Australia, 3122
        • Centre for Human Psychopharmacology - Swinburne University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

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)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / 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

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
18 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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
18 weeks

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
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
18 weeks
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
8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Melbourne

Collaborators

The University of Queensland
Swinburne University of Technology

Investigators

  • Principal Investigator: Jerome Sarris, PhD, The University of Melbourne and The Melbourne Clinic

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 13, 2015

Primary Completion (Actual)

May 31, 2018

Study Completion (Actual)

May 31, 2018

Study Registration Dates

First Submitted

August 13, 2014

First Submitted That Met QC Criteria

August 17, 2014

First Posted (Estimate)

August 19, 2014

Study Record Updates

Last Update Posted (Actual)

October 15, 2018

Last Update Submitted That Met QC Criteria

October 10, 2018

Last Verified

October 1, 2018

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 137/14

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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