St. John's Wort And Kava In The Treatment Of Major Depressive Disorder With Comorbid Anxiety

Inclusion criteria

• Any person male or female aged 18-65 presenting with a diagnosis of unipolar depression confirmed by CIDI auto (quantified by BDI) and an anxiety score on the DASS of 8 or above i.e. the mean (quantified also by BAI)

Exclusion criteria

• Psychotic/ Bipolar illness
• Current or < 6 month significant suicidal ideation
• Diagnosed hepato-biliary disease/inflammation
• Current or < 6 month substance abuse disorder including alcohol
• Current or < 12 month use of kava, St. John's wort,
• Current or < 1 month of synthetic antidepressants or benzodiazepines
• Previous reaction to kava or St. John's wort
• Medications that maybe pharmacokinetically altered via St. John's wort including:

• Amitriptyline anti-coagulants e.g. phenprocoumon, warfarin,
• Anti-fugals e.g. voriconazole,
• Anti-histamines e.g. fexofenadine,
• Benzodiazepines e.g. alprazolam,
• Chemotherapeutics e.g. irinotecan, digoxin, HIV medication (anti-retrovirals), * Immunosuppressants e.g. cyclosporine, methadone, OCP,
• Statins e.g. simvastatin, warfarin (Henderson 2002; Izzo 2004).
• However this interactions are based on case studies and theoretical interactions and are regarded to be induced by hyperforin (a constituent of St. John's wort); low or non-standardised hyperforin preparations are regarded to not induce drug interactions as little induction of P-glycoprotein and CYP P450 enzymes occurs (Madabushi et al. 2006). Although in vitro studies have confirmed that kava and the isolated kavalactones modulate certain CYP 450 enzymes, no documented evidence of human kava-drug pharmacokinetic interactions exists (Mathews, Etheridge & Black 2002; Singh 2005)
• Seeing a psychologist or counsellor currently or in the previous month.
• Non-English speakers.
• Pregnancy