What do dementia stages mean? This is episode 1 of the highly requested dementia explained series. When someone says my person with dementia is at stage 4 or 5 or whatever, they are talking about the Global Deterioration Scale. Think of it like a roadmap or a framework you can use to get an idea of how far progressed your person with dementia is into Alzheimer’s specifically. Stage 1: No cognitive decline. Normal memory and thinking. Stage 2: Very mild cognitive decline (age-related forgetfulnes