It is written that Azilect makes irreversible changes in the brain. "Rasagiline (Azilect, TVP-1012, N-propargyl-1(R)-aminoindan) is an irreversible inhibitor of monoamine oxidase-B". So the question is, why do we need to continue to take it? The effect was irreversible. Why isn't a few doses sufficient for a lifetime? I anticipate some will say things like, its so the manufacturer will make more money. Please...?