We are also forced to use our brains a lot more. ADHD induces novelty seeking. This exposes us to new information, which requires processing. It also messes up habit forming, so normal tasks require far more mental effort.

Since intelligence is a little like a muscle, it grows with exercise, it makes sense why a good number of people with ADHD score higher. It’s one of the few useful side effects.

On a side note, raw intelligence does remarkably little to help with day to day tasks. No matter how much you throw at it.