Curate, connect, and discover
Proof: As shown in the screenshots in this post, there is a call with Seven where he says he talks to himself a lot, and the MC has the option to respond "I heard people with adhd talk to themselves a lot..." If you choose this option, he says "Yeah!" and proceeds to describe more ADHD symptoms he has (distractability and fidgeting, and arguably hyperfocus.)
It's my birthday so I'm giving more stuff too: I love Seven as canon undiagnosed ADHD. He even self-medicates with caffeine. I resonate with him so much. I'm certain that at least one person on the writing team has ADHD, he's just so spot on. Please play Mystic Messenger