Do you doubt the existence of autism? Dyslexia?
Probably not.
Sorry that it can't play the role in your polemic that you were hoping for.
BTW. I always considered ADD, ADHD, etc. to be a bit of a fake disease, a product of environment, but I'm no longer sure. I've been struggling with depression and anxiety for many years and responded relatively well to SSRIs which stabilized my mood and helped me quit the recurring panic attacks. The problem is not gone, but with a little more stable emotional situation I managed to figure out that what really causes most of my problems now is total lack of focus. I can't hold my attention on any kind of work-related task (the task doesn't matter; what matters is that it's work) for more than 30 seconds without compulsively seeking something else to do. Be it HN or IMs. With no easy distraction source available, I'll get anxious and sleepy. I can be perfectly well-rested but will still occasionally get sleepy at work just because I refuse to distract myself with Hacker News. A considerable amount of my mental energy goes to fighting this and forcing myself to focus. Now that I've finally dug that up from underneath the layers of anxiety, it's going to be a topic of the next conversation with my doctor.
#HNTherapy
Also, this is what I got googling for ADD[2]. What the shit?
[0] - http://slatestarcodex.com/2014/09/10/society-is-fixed-biolog...
[1] - http://lesswrong.com/lw/2as/diseased_thinking_dissolving_que...
It's interesting that the Ketamine research comes to the conclusion that depression is not a mental imbalance but is a product of the environment causing structural changes in the brain - this seems more in line with what eg ADD and Depression ACTUALLY are - it's not that I can't focus because I caught something from my neighbour - I can't focus because I'm berated with stimuli and I can't pick just one thing to focus on. I'm not depressed because my brain isn't producing enough seratonin, it's because I've been wore down supressing my wants and needs and extended myself trying to make other people happy or overstimulated myself or whatever.
We don't know but the picture is getting clearer - depression isn't a common cold that you need drugs for - it's more like liver disease caused from chronic drinking. Stop drinking, and let your liver recover only science just barely understands the processes of the psyche and environment that cause those physical changes in the brain yet.
Addiction itself is very much an obvious facet - it's not a degenrate behavior but a degenerative structural change to the brain that cause inner behavioral and perceptual changes that need a physical restructuring of the brain to overcome.
It will take time but science will get clearer. The problem is that there are many motives - the whole "sitting is the new smoking" awareness is evidence that we focus on the wrong things - why is this just coming out now? because there is no profit motive to fund that research.