Our daughter, who has ADHD was born not breathing and blue. Her APGAR scores were 0. Her brain was without oxygen for a period of time. She did start breathing and had no symptoms until she was supposed to be reading.
In 2nd grade she was in remedial reading and in danger of being placed in special education classes because she was unable to meet minimal reading required for her grade.
We suspected ADD in spite of the fact her behavior was exemplary. One month after she began medication, her reading skills were two years ahead of her age. She continued medication and finished HS with honors and was inducted into the honor society. We never needed to remind her to take her med's. She knew the difference had too dramatic an effect. In fact, her friends and teachers never understood how profoundly she is affected by ADD until they experience being around her on a day she does forget.
Was it Brain damage, hereditary or some other cause? Who knows. Is it real and does medication work? Absolutely.
An issue you and I are in complete agreement on.