Hlelp my aunt with alzeihemers

My aunt(mother's sister) is 83 years and is showing signs of alzeihemers. My mother's brother too suffered from that, so may be it runs in the family but no one survived so long earlier in their family. My aunt is a spinster and has led a very independent life. She was a professor in a University and led a very active and dominating life style. She was fine after her retirement. Now with the increase in age, she gets into fits of depression and cries. She almost behaves like a child and keeps on asking the same question again and again. She is able to identify very few people in her family. Her questions are disjointed and sometimes make no sense. I know that it cannot be treated but can someone advise on some medicines which might make her feel better. We just want the rest of her life to pass smoothly. Please someone advise.