Well adhd takes shape differently depending on the individual. I used to be unable to sort impressions at all, to the point where I could hear every convo going on in a room all at the same time. Couldn't ignore any of them to focus on the one that was relevant. When my brain ran outta power and fucks to give, I just turned off entirely and was near unreachable.
I have trained and worked past that so now that's no problem anymore. But books still are (rants and the like aren't but that's because they're usually just within the amount of text I can read of the same type without my head giving up) and I just don't do well with descriptions at all. The way books describe environments especially distracts me, not to mention the actions that it describes people doing mid convo or the different facial expression implications. My brain gets stuck on certain words, their sound, their many possible meanings, and eventually the words become meaningless to me. After that it becomes a grey block of nonsense.
I have actually illustrated the concentration problems I used to experience (along with this phenomena I just described) as the experience of a character: