Brainwaves are one thing they measured when I got my second diagnosis (the first was questionnaire-based). I was told my theta waves (associated with sleep) are unusually high and my beta waves (thought & activity) low.

Understanding that hyperactivity is secondary to an underactivation of the brain in ADHD was very enlightening for me. Since then I’ve taken to napping whenever I feel tired instead of deathmarching through these phases whenever possible. Yes, it messes with my sleep schedule a little bit but it’s better than the alternative.