Considering the very early effects of dementia start to impact people sometimes decades before it becomes bad enough that they are diagnosed, it's certainly possible that extreme coffee consumption is some kind of self-medication mechanism.
Anecdotally, I've seen this a lot with adults with undiagnosed ADHD (including myself until 26). Caffeine can be a (very shitty) alternative to proper stimulant medication that people don't realise they actually need because of a medical issue. So the end up drinking 4-5 coffees a day instead.
Anecdotally, I've seen this a lot with adults with undiagnosed ADHD (including myself until 26). Caffeine can be a (very shitty) alternative to proper stimulant medication that people don't realise they actually need because of a medical issue. So the end up drinking 4-5 coffees a day instead.