Gamemaster Law does touch on this topic under mental diseases. A nice table to roll on with various mental illnesses listed. I have used it before, though it requires some extrapolation on the GM's behalf. Basically, disorders have degrees of severity, from minor cleptomania to extreme cleptomania, as an example. Once, this table destroyed a PC after he suffered an extreme rr failure and then roled pedophilia. He absolutely refused to even attempt playing it and wouldnt let me reroll, but rather made a new PC. Admittedly, I wanted to go with necrophilia instead, but he didnt like that either.
lynn