G.D.
I haven't read other questions pertaining to ODD. My sons dr did say it is one of the most common diagnosis along with ADD. I have two diagnosed with ADD/ODD. I agree it's exhausting! Even for my other two kids!
One does much better with medicine and the other does much better without. I have to be very proactive about almost everything (a fight over who is sitting in which seat in the car can delay us for quite a while). I find structure, rules, and responsibilities are very important too. Honestly it all boils down to knowing your kid, advocating for your kid, and keeping yourself healthy. It's certainly never easy-but you learn to celebrate small milestones.
In 2nd grade my son refused to go to school most of the time, would hit kick, punch, throw things. He was very defiant/borderline physical with an inhome therepist (took everything I had not to step in). But, slowly-now that he's in 4th he is rarely defiant and finally having more good days than bad. Just had to keep on keeping on!