It's important to note that ADHD diagnosis
as with all psychological diagnoses is subjective in the extreme. The DSM-IV lists clusters of symptoms that are indicative of various disorders, and it's how many of those various symptoms that you match that qualifies you as having this disorder rather than that disorder. The result is, what's ADHD to one doctor is depression to another, and normal to a third. There's far more guesswork than science involved in psychological diagnosis.
My own ADHD diagnosis was questionable at best. I spent a day doing various concentration, memory and IQ testing, and was returned the following diagnoses: Depression along with the possibility of Borderline Personality Disorder, and I apparently fell midway between an ADHD sample and a 'normal' sample. Thus, it was suggested that I start antidepressants right away, and if it really meant that much to me, I could start treatment for ADHD as well.
Now Bob here can testify to my status as ADHD, as well as the progress I've made in the last 3-4 years. I've gone from a morbidly obese, depressed forklift driver to a much less obese (yeah, yeah, I've still got a ways to go

) student at a major university, bringing home straight A's. All this as a result of having the strength of the conviction that depression was not my primary issue, and taking the time and the interest to pursue and manage my own treatment. It took me nearly two years to find a psychiatrist that was willing to take enough interest in my condition to really help me, and a proper medication regimen, along with a good bit of work with books and a psychologist has changed my life. That's not to say that I still don't have challenges, but I'm far better off than the nigh-suicidal, partially ADHD diagnosed drifter that showed up on these boards in 2008.
As to my 'depression' diagnosis, I was started on Celexa immediately; a move which drove me into a depression that very nearly ended in my death. Had I trusted the doctors I was working with originally, I may well not be here today, because their own preconceptions that coloured their interpretation of the DSM-IV had led to a poor diagnosis. Treatment of Borderline Personality Disorder was never started, as I read the symptom list for that disorder and rejected it as a diagnosis.
The moral of my story is this: If you know you're ADHD, and you're experiencing significant and lasting symptom relief from ADHD meds, you're ADHD. Don't let anyone tell you otherwise, because it's simply their interpretation of the DSM-IV versus your own that is at issue. Certainly you can decide to defer to their interpretation, as they are likely more educated in this field than you (I'm making assumptions, and if you're dealing with an MD, you probably know more than he does about ADHD), but you have a
far larger stake than anyone else in this, it's your life that's at issue here, rather than a very small portion of their paycheque. Don't allow passivity to affect your chances at a better life.