I personally love Lake's bursts of philosophically fatalistic mood. "You can suddenly just die, everything you have can be lost", and I'm like: "I just had supper, who starts a conversation like this?
I don't know if I can judge - I don't have ADHD, so my understanding of it is anecdotal at best.
But if YOU feel ADHD vibes from Lake - then you very well might be right. After all, the characters in Dawn Chorus have been impeccably written so far.