Hello. I'm glad to have found this board!
I have a daughter who was diagnosed with ADD in first grade. She will go to 8th grade this fall. She had all of the typical symptoms; easily distracted, inattentiveness, impulsiveness, etc. She LOVES school but gets easily discouraged when she's having a hard time staying on track.
I was diagnosed with ADD at 40 years old. I'd pretty much suspected that I had it after learning a lot more about it during my daughter's diagnosis. I always knew something was 'different' about me during my childhood but who knew what ADD was back in the 1960's?! My parent's, who are in their 70's almost seemed to feel bad ... they knew I was 'spirited' but weren't quite sure how to deal with it properly back then, I'm sure. So my diagnosis was pretty much a relief. Now I can use it as my excuse for my younger years. ;-)
After a lot of research, I'm pretty sure we've found our answer to ADD. I very recently saw a Dentist who specializes in TMJ and crossbite (which I've had for years...). She asked me if I snore and clench my teeth when I sleep. My family has told me this many times over the years, so yes. :) She then asked me if my children snore so I told her that my daughter does. She asked me if she had ever displayed any ADD tendencies! When I told her she was diagnosed 7 years ago, the first thing she said was that it's time for a mother/daughter overnight sleep apnea test. I was diagnosed with severe OSD and my daughter was moderate OSD. We've basically been living off of naps for a long time now.
My tonsils/adenoids are fine, but because of my crossbite/TMJ, my tongue tends to slide when I sleep, causing interrupted breathing. My daughter needs to have her tonsils/adenoids removed to resolve the sleep apnea.
Sorry this got so long! I am thrilled that this has come to light for us, and wanted to give others who have been dealing with ADD/ADHD some hope. Google: Apnea and ADD