It is beneficial as antidepressant (it is the only thing that worked for my bipolar, it made me not commit suicide several times, it helped me find a job too), it lowers tolerance to other drugs, it is beneficial as neuroprotectant, it is also even proven to cure rabies!! Amongst other things. I will publish a list of journal articles I'm collecting once I am done.
As for liver damage, the gall bladder thing is a fact. It seems to be not widely understood but it happens to heavy users. I guess you can say that if you feel it, then this is a sign that you are crossing the line. Maybe FnB will shed more light on this. In any case it is by no means a good thing, but it CAN be avoided as my experience has proven over the years. And as I mentioned - abuse of ANY substance will lead to toxicity, even beneficial ones like Ketamine. However, Ketamine has been used medicinally for more than 40 years, and it is medically used as an anaesthetic for children and people with liver problems due to its extreme safety.
But again I say: the abuse of ANYTHING *will* cause toxicity.