There is a very simple solution regarding this; a blood test can be taken at 1 or 2 months after starting treatment, or as your doctor advises. This is regardless of the medication used, whether Kava or conventional medicines which also require blood be checked for liver function via a simple blood sample.

Tricyclics are known to potentially cause liver damage, as are SSRIs particularly where patients are also abusing alcohol which is also particualarly common with PTSD and/or taking benzodiazepines in conjunction with SSRIs

You should have had a blood test after starting treatment with standard practise antidepressants, and if this has not been done, it would be worthwhile requesting it be performed. It depends mostly on the level of healthcare in the country. In Germany it is performed automatically 1-2 months after starting medication, yet in England I have heard of someone taking this medication for over ten years and a blood test was at no time discussed.

It does also depend on dosage levels, but also on therapies where the load is increased on the liver due to more than one medication being taken.

This would apply where SSRIS (eg Zoloft, Citalopram, http://en.wikipedia.org/wiki/SSRI ) were used in conjunction with benzodiazepines (eg Xanax, Clonazepam, http://en.wikipedia.org/wiki/Benzodiazepine). Treatment with benzodiazepines needs to be administered with care due to abuse and dependency issues as does with some SSRI medication.