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NCT Number: NCT02219880

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

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

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Key information

Conditions

Generalized Anxiety Disorder Anxiety Disorders Mental Disorders

Age range

18 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Royal Brisbane & Women's Hospital, Brisbane, Queensland, Australia

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About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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)

Treatment and study plan

Kava (240mg of kavalactones per day)

Dietary Supplement

Kava 60 milligrams per tablet = 240mg of kavalactones per day

Other names: Kava, Kavalactones, Piper methysticum

Placebo

Dietary Supplement

Inert tablets containing vegetable fibre matched for colour, size and consistency to active arm treatment.

Primary outcomes

  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 outcomes

  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 outcomes

  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

Sponsors and collaborators

Lead sponsor

University of Melbourne

Other

Collaborators

  • Swinburne University of Technology
  • The University of Queensland

Registry information

Acronym: KGAD

Important dates

Study start
2015
Primary completion
2018
Study completion
2018
First posted
Aug 19, 2014
Registry last updated
Oct 15, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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