LocalH parent
To be quite honest, demanding an ADHD individual deal with focus-thieves on their own and claiming that it is "toxic" to set boundaries that enable them to do their best work is kinda like expecting a recovering alcoholic to work at a liquor store and saying that it's "toxic" for them to refuse to do so.
Except it is toxic; you can't redefine the behavior because of someone's affliction no matter how unfortunate that may be. If you have Tourette's with coprolalia, you can't go around the office yelling "cunt" at the top of your lungs and expect everyone is okay with it, or that you deserve an accommodation.
Except it’s absolutely not if managed appropriately.
If they’re behaving that way unannounced then yeah, it’s not good but if the manager is aware then all that’s needed is “hey team, Andy is on the spectrum and prefers to work this way. Please try to accommodate, any issues let me know”
Those requirements aren’t challenging to meet for a coworker.
It's not toxic to say "all these distractions and interruptions stop me from doing what you pay me to do, here is what I need to do in order to perform my best work". It's toxic to tell that person that they're being toxic, which ADHD people tend to heavily internalize.
It's toxic to say your coworker asking for help is a distraction when all people are supposed to be there to collaborate and get things done together.
Imagine someone comes to your desk and says they need help with something and you say "Please go away, you're distracting me" or you simply ignore their presence. How would they feel?
I'm not saying OP is doing it at that level but I think you can see my point.
Follow the rules and chain of priority. Your manager knows what is important to them let them decide. Other pms need to go through proper channels.