@nana75165 I'll believe when Mayo says it's so....

My first inclination was to reply - well, age plus pain plus fatigue (poor sleep) plus medications affect cognition in just about anyone. Then I did some reading, and this article seems to summarize what the few studies out there concluded. Pain, depression (common with pain), cardio-vascular disease (common with inflammation), medication and lack of exercise all contribute to "brain fog" or apparent cognition. But RA patients tested alongside their age-mates are about the same... https://www.arthritis.org/diseases/more-about/ra-effect-on-the-brain
Here is one thing I do know - steroids are a big problem for me - when I am on them for my breathing, my mind is worthless for as long as a month or more afterward - my asthmatic daughter says the same. And when my Mom was living, I knew within 48 hours if a new doc was trying a steroid med on her again. They are very common in treating RA flares too, so if you have been using them it could be part of the issue.
Sue