That's an excellent question and I'm glad you asked me.
There are indeed some professionals who often speak about contented dementia. To be quite honest, I don't believe in it. Contented dementia amounts to symptoms of a disease being expressed. It's not that the person is content, but rather that brain plaques have disrupted their neurotransmitters, causing what appears to be expressions of joy. No one has ever told us that they feel happy, even though they appear to be. I honestly find it sad to hear people say this, and I've often heard some health professionals who practise medical assistance in dying say that when people experience contented dementia, they are happy. We just don't know.
I can tell you today what behaviours would make me feel that I'm losing my dignity, for example, if I no longer recognized my children, if I couldn't manage to go to the bathroom alone or if I couldn't eat by myself. These are behaviours that I've mentioned already and that are readily observable.
Some people won't like what I'm going to say, but I think that contented dementia is just a concept that some caregivers are fond of. They want to believe that the patients are happy. But we don't know if they are and we can't assume that they are, hence the interest in advance requests.