My Mum was diagnosed with Picks Disease 3 and a bit years ago, and seems to have declined very rapidly. My Dad is her full time carer. They have an AMAZING mental health nurse who comes to visit them (I genuinely can't sing his praises enough) and he's always very straight with my Dad.
Yesterday when he came to visit my Dad asked him about the likely progression from here (she's lost a lot of her language comprehension recently) and what is going to happen from here. He told him that the average time from diagnosis to death is 4-7 years. This isn't a shock, and is actually kinda reassuring (I can't imagine her living like this for the next 25 years) but I can't find any information on what indicates which end of that scale she's likely to be? She's 59 this year, so she's still really young, but the progression has been really fast, 3 and a half years ago she was still working and just really forgetful.
My Dad is still pretty young for this stuff too (he's 68) and we talked about how we've done a lot of mourning for the person she was, but it still won't be any easier when it's all over.
I guess my questions are - how do we know (and by that I mean guess) how long we're likely to have her, should we start preparing for the inevitable sooner rather than later? And how should I support my Dad?