Wikipedia is not the place to publish original research.  Wikipedia will only give a "balanced view" if such a view can be supported with citations from published literature, preferably peer-reviewed scientific literature.  Equally important, Wikipedia is a reference encyclopedia that has an obligation to note that this hypothesis is not currently accepted by any mainstream, reputable medical organization (CCHR doesn't count, as they are neither reputable nor are they a medical organization).  

Perhaps, instead of attempting to convince the Wikipedia audience as to the veracity of these claims, you would be better off attempting to publish research and convince scientists and researchers of the validity of these claims using evidence.  You mention that you are a psychologist.  I do not know about psychologists across the pond, but in the US, the American Psychological Association, the specialty society that represents and speaks for American psychologists, has been quite clear in stating their support for the mainstream view that ADHD represents a serious neurological behavioral problem.  The American Psychological Association has also not endorsed this Social Construct hypothesis, and many of their statements contradict this hypothesis.

In fact, the APA even has a page set up specifically for ADHD:
http://www.apa.org/topics/topicadhd.html

Now, as I mentioned, I am not as familiar with practice in the UK, but I did manage to find the NICE clinical practice guidelines for ADHD.  They can be found here:
http://www.nice.org.uk/nicemedia/pdf/CG72FullGuideline.pdf

In any event, the problem has nothing to do with anyone being "wedded" to any notion, but rather that the proponents of this hypothesis have published very little research and have so far failed to convince the vast majority of researchers in their field as to the merits of their proposal.  First must come the research, the evidence, independently verifiable information that can be cited to support the hypothesis.  That must come first, before you can expect to see any sort of "balanced view."