This study will examine the utility of plasma and urinary based biomarkers for the anxiolytic properties of kava. The investigators will conduct a one week, double blind, randomized placebo controlled trial of kava, dosed at three 75 mg capsules per day, vs placebo, in adults with generalized anxiety disorder.

This study will examine the utility of plasma and urinary based biomarkers for the anxiolytic properties of kava, a natural dietary supplement. The investigators will conduct a one week, double blind, randomized placebo controlled trial of kava, dosed at three 75 mg capsules per day, vs placebo, in adults with generalized anxiety disorder. Clinical measures of anxiety, blood, and urine will be obtained. Biomarkers of interest include PRKACA, cortisol, urinary TCE, and NA5HT. Participants will be assessed pre- and post-treatment. The participants will also be followed for 12 weeks after the end of treatment to identify any potential rare adverse events, particularly liver toxicity, that appear in a delayed fashion.

Inclusion Criteria:

• Adults ages 18-50 who meet Diagnostic Statistical Manual (DSM)-5 criteria for GAD as the primary psychiatric diagnosis
• No more than one failed therapeutic trial of an FDA approved medication for the treatment of GAD
• Score of>14 on the Hamilton Anxiety Rating Scale at both screening and baseline
• At least a 4 (moderate) on the Clinical Global Impressions Severity Scale at both screening and baseline
• Females of potential childbearing status must use adequate contraceptive precautions.

Exclusion Criteria:

• Unwilling/unable/unsafe to stop psychotropic medications (if on any) for the duration of the study
• Inability to refrain from acetaminophen, alcohol or other potentially hepatotoxic substances
• History of liver disease or current liver disease or clinically significant elevation in serum liver chemistries
• Unstable medical or neurological condition
• Positive urine drug screen for substances of abuse
• Active substance abuse/dependence
• Lifetime history of a psychotic disorder, bipolar disorder, PTSD or Obsessive Compulsive Disorder
• Any significant risk for self-harm or suicidality as determined by the principal investigator or suicide attempt within the last 6 months
• Psychotherapy newly instituted during the 6 weeks leading up to enrollment in the study. Subjects established in psychotherapy without change during the course of the study may participate
• Montgomery-Asberg Depression Rating Scale (MADRS) > 17 (moderate or severe depressive symptoms)

Participants were enrolled and analyzed as described in the protocol

1 year and 6 months

Guidelines for reporting adverse events were the same as the clinical trials.gov definition.