I have noticed a man I know well whom I strongly suspect suffers from ADHD turning discussion about his activities too often. He can discuss in detail what he did during the day and why, even when that is of limited interest to his audience.
I can find a commercial website suggesting that ADHD causes one to excessively talk about oneself, and considerable anecdotal evidence, but nothing authoritative.
Is there strong evidence that ADHD causes excessive self-centered talk?