I think the patient has a right to know. I certainly would. My Mum has dementia and her deterioration over the last few months is heartbreaking. I know if she knew this was going to happen to her, she would have ended it.
Whilst I was sitting with her in the Care Home yesterday, holding her hand, she looked up at me and said, how long is this going to go on for Den, I had to hold back my tears, and just reassure her.
Cailin - if this patient has early stages of dementia I know there are drugs that will slow it down - but you have to be persistent - the GPs seem reluctant to try these on some patients.
Good Luck xx