Meds: Is More Better?

I take a large dose of a second-generation anti-psychotic medication that I've been on for 18  years. It's my go-to medication when I struggle with voices and delusions. Lately I've found that my current dosage isn't enough to get me through even a "regular" day. So I'm increasing the dosage by 33 percent, which is helping me. The trade-off is that it contributes to my negative symptoms of schizoaffective disorder, which isn't helping me. So is more better?