Well, it's not for a sore knee. Is there anything more unapproved than an irreversible disease that destroys your mind in the space of a few years? It's not like cancer, from which you might be cured, or at least with which you can have a meaningful life until your eventual death. It is a slow motion process of erasure that is well on its way at the moment of the first diagnosis. Taking the wrong medicine could shorten your brain's life of how much, a year perhaps? Still worth trying.