[bsvalley]

It seems to be a lack of confidence or a miss understanding of the requirements. In other words, no one really understands what has to be done and how to do it properly. If you understand the requirements and have enough knowledge about the domain, you should be able to articulate your thoughts clearly and simply. This goes for code reviews, integrating your work with your peers, splitting the tasks into smaller tasks, convincing someone about a technical choice, etc.

You and the 'ADHD' coworker can't seem to communicate properly about the actual topic (project, tasks, etc.). I'd suggest to sit down together and to go over the requirements. Slowly but surely. If your coworker knows exactly what you're working on and why (and vice versa), then the style shouldn't be the issue. We're all different and we all have different styles. It doesn't really matter.

[throwaway515100]

There is no doubt nobody fully understands the requirements (in our industry?) and that's good advice, being pragmatic. However, even when the requirements are clear, it's a pretty chaotic process which is hard to follow. I wouldn't discard this as simply being a style issue. This person seems pretty nervous when discussing things, so there is some struggle. I can try to clarify the requirements for everybody's sake (including mine). Please don't label this person as the 'ADHD coworker' though.