This is a very difficult character to play. (Interesting thing is that both of this year's leading acting winners had very difficult thing to do, because they had to play disease, though both of them had a different issue to solve.) At the beginning of the film, Alice is relatively healthy. There are only some small circumstantial evidence about some starting disease. But at the end of the film we see Alice at an absolute breakdown, when her illness is controlling her absolutely. This change is very slow and it is not an easy thing to stay realistic in this reinvention. But Moore is so great that we are not even realizing the change. It is not that she would underplay it, but she really sensitively shows the little steps that the Alzheimer's disease is making. As an example of this change, the first scene of the film shows Alice lecturing. And then, later in the film, when the disease is advanced, she has a speech in front of other people affected by it. The difference is very big and Moore handles it quite great.
What I really adore about this performance is its authencity. Many scenes are very subtle, but Moore finds something interesting in them and transports it into her performance. For example the scenes at the doctor are simply fantastic. He asks her some questions and before she answers, we can absolutely see her thinking about it. What is also perfect about it is the way she tries to look as healthy, as possible. That is probably just the way everyone would react and Moore is perfect in showing this.
Disease as such would certainly affect your personal life. That's why it's very important to have chemistry with your co-stars. Her husband is played by Alec Baldwin and I must admit that I didn't like him very much. He was very bland in his role and I think he didn't really catch what would a man in his situation have to go through. But his chemistry with Moore is surprisingly very good. It might be because it's really difficult to not have chemistry with Julianne Moore. Also her chemistry with her children is very good, though the direction doesn't really focus on them, except from the one played by Kristen Stewart. It would be Stewart's chemistry with her siblings that I would have had complaints to, though she was really very good in her role, as well.
Though Moore was authentic most of the time, there are a few moments in which she overacts a bit. It's some kind of habit of Moore's that she always has a few scenes throughout her performance that are overacted. For example even her SAG clip was one of those moments. But that is really a negligible mistake and to me it's even sympathic...
