Anecdotally, I’ve had conversations with more than 50 people who say caffeine does not affect them who likely have ADHD or some kind of attention disorder.

For example, I was at a gas station this weekend buying coffee during a small road trip. The cashier and I we’re making small talk that it was early and I wanted my morning coffee, they said oh caffeine doesn’t affect me. When I hear something like that I usually ask if them if they have ADHD and they’ll typically respond with a yes.

There is definitely bias in my non-scientific survey, I only ask people who make the comment about caffeine not affecting them.