Can a person themselves cause dementia or Alzheimer;s by not continuing doing things be involved in life?

If one does not stimulate the mind (read, hobbies, socialize , etc) and be negative can that strongly influence one to develop dementia. I am asking because my mom has it .For many years , she was not involved in life. She stopped going to church and other social functions , slowly stopped her hobbies and became negative. I did what I could to help. I was there for her when her health deteriorated since I was the care giver.She is now in a nursing home. I guess if there was something I could have done to prevented it.