That being said, if they always lose, that is still pretty much discrimination. But it's less discriminating than simply being excluded from the list at all, because in the event that TWO organs are available and two people need it, then both will get it. Whereas before, the organ just gets put in storage and the person with the mental illness wouldn't be able to get it at all due to not being on the list. An important thing, which I don't think Sylvana took into account.
I agree, in a world where spare organs are plentiful, preventing someone with mental disorders from being eligible is discrimination. However in the real world there are always far more people needing organs than there are organs available.
A more accurate example of how reality is would be: You have a single replacement organ and 10 people who need the organ. They are all equal in every way except that 1 has a neurological disorder. Who gets the organ?
The basic rule at play here is triage.
The person with the highest chance of survival is given the limited medical resources needed. Unfortunately in the grand scheme of things, having a mental disorder places you lower on the triage list. People with neurological disorders will be placed behind those people who are effectively healthier, behind all the healthy people who will also never get the organs. Until replacement organs are available in sufficient quantities to finally treat all the healthy people on the lists, there will be automatic exclusions.
In a perfect world automatic exclusions wouldn't exist and there wouldn't be discrimination, but one must remember that the medical world is not politically correct nor can it afford to be.