Should I agree to my husband's meds, even if he disagrees?

My depressed and delusional husband (67) refuses to believe (or more kindly, "lacks insight") his diagnosis of Parkinson's dementia AND major depression with psychotic features. However, he is very smart, not suffering other cognitive problems, and most of the time can articulate his wishes. Since 2018 when he was first diagnosed with Parkinson's, he has refused treatment (from neurologists, psychiatrists, physical therapists). Why? His reasons, as I see it, are a complex combination of a lifelong resistance to medicine and newfound fears and delusions (for example, he insists he has no health insurance, owes thousands, and is being sued by medicare). I have a Med-POA. Since his new diagnosis of Parkinson's with dementia in March (which landed him a short stay in a geri-psych hospital) he's been on namenda, seroquil and anti-depressants. Thus far they seem to provide no relief of his depression and delusions. He's getting by--not well, but not in danger. (We don't live together, he's in independent living nearby with 3x meals and 2x per day aide drop-ins). I still hope we can find an effective medication for him. So here's the problem: We go to his psychiatrist, where my husband insists he doesn't want any increases or changes in medicine -- would prefer to be off them altogether. He doesn't like the way they make him feel, he says, and then argues that his problem is not in his head. (This is, again, delusional. He believes his body is failing systemically and doing things like "sweating excrement." Yes, we've ruled out physical ailments). So then the Dr. turns to me and says "Well, you're the MPOA, it's up to you to say yes to a change in his meds." What? But my husband's not in coma, he's sitting RIGHT THERE -- saying he doesn't want it. And his refusal is not completely illogical. He's battled depression his whole life and has never wanted to be on meds for it. Now he doesn't want anti-psychotics. Anyway, so I'm put in the terrible position of either (a) directing his meds against his wishes, (b) discussing, arguing, begging, and cajoling him to try news meds, or (c) letting him make his choices. On the one hand, I feel like I should just override his wishes and tell them to go ahead and change his meds. If my husband doesn't want to take them, that's his choice but at least I will have fulfilled the responsibility he conferred on me when we did our MPOAs years ago. On the other, he's capable of understanding why certain meds are advised and of articulating why he doesn't want them -- a test for competency that has led other Dr.'s to reject my attempts to override his wishes. Apparently competency is a fluid definition. Also, this is a gray area because, let's face it, different anti-psychotics may or may not help. It's not like I'm faced with a decision to give him surgery to save his life or keep him on a respirator. It's more like making a decision about giving chemotherapy to someone with advanced cancer. In the end, it comess down to a fundamental difference in the way my husband and I have always viewed life. I think it's worth saving at all costs and he doesn't. (When I went through a bout with cancer five years ago and was faced with an ambiguous choice about chemo, he suggested "don't do it". Good thing I DIDN'T listen to him). So what to do? We're seeing his psychiatrist this week. Change his meds in the hope of improving his state? Let him live with his delusions?