R.J.
ODD & ADHD are EXTREMELY different, although many people (in appropriately link them).
Its almost always found together in Spectrum kids (ADHD+ODD+ASD) totally appropriately... But it gets lumped into stand alone ADHD waaaaay often.
It helps to understand that BOTH argue... Just for different reasons.
EX) The sky is blue
ODD. No it isn't. You can't make me say it is!
ADHD. Not really. Right now its more of a grey ish white, because of the cloud cover. This morning it was pink. Before tornados its green. At different elevations it appears different colors, from a pastel nearer to white, to a deep lapis. Depending on moisture content. And, of course, REALLY... The sky is BLACK. We're just seeing light bounce off water vapor. Space is black. Except. Space isn't REALLY black....
ODD is responding to the PERSON. White/black. Yes/no. Etc.
ADHD is looking at 1001 variables, and really trying to figure it out (or share something they figured out).