Delusions are the worst, once they are too far gone there's no sense in trying to convince the person it's not real. We've been through it with a family member many times, the worst part is that it starts slowly, but they hide it so well or they self isolate and alienate everybody. Once the signs are there, they are already too far gone, broadcasting, paranoia, persecution, grandeur, telepathy, false memories, you name it. If it were only voices, I think that could be managed more easily than delusions. Not sure if it's true that relapses cause further damage (neurotoxicity) but so far only the neuroleptic shots have proven to be reliable and prevent the next manic episode. Regrettably, these cause a host of other issues, like depression, lack of motivation or pleasure and so on.