It’s frustrating to watch those you care about make irresponsible decisions, but there are some options that might at least help some. I might start with a legal consult with an elder law attorney in the jurisdiction where your parents live. They can explain the law there and what is required to prove incompetence and get guardianship. It’s a huge responsibility though. I would not attempt it now after discovering how difficult it is to help elders who are resistant to care.

But, even if you don’t seek guardianship, I’d explore whether the parents have properly executed durable power of attorney, healthcare POA, advance medical directive, etc. and ensure you have access to the originals. If your dad is away and gets sick, you might need quick access.

I hope things work out. It’s difficult to see someone make poor healthcare decisions, but sometimes it’s ultimately their decision to make. If your mom is having mental distress, I might inquire about meds from her doctor. Even without added stressors, dementia often causes anxiety and depression.