Dealing with paranoid psychosis

I have a relative who was diagnosed with paranoid psychosis about a year ago—back then, they were totally fine with starting medication and staying in the hospital. But the illness has resurfaced, and this time things are different. They've become aggressive—just verbally, though—and they’re completely refusing any kind of treatment because they're convinced everyone is out to get them. I'm trying to understand what the long-term consequences are if we don't manage to get this treated.