I thought it was somewhere on Andreas' forum.... how THC is broken down in the liver..stressing it and causing it to produce more stones.... I will look a little harder for the link.....
As for the psychosis stuff.... well I agree, there are many good articles that debate both.....
My gut tells me that smoking weed can be more of a way to self medicate and escape reality and isnt nessesary when you reach a more balanced state....
just my 2 cents......