Several supplementary points.
First, let us simply take for granted that pharmaceuticals are in fact trying to profit by a proliferation of conditons requiring medication. In geeneral forseveral decades consumer-product manufacturers have prolifeated special products: Not just string beans and salf-free string beans but string beans&onions, etc. It sometimes becomes difficult to find the "straight" product among the bewildering display of slight variations. (Consider the number of producs which carry the label "original" as part of their name: e.g., Original Pepperidge Farm White). Probably at this poin this thread 'rhymes' with the threads on music. In other words we are dealing with the political economy of "late" capitalism. [Scare qutes because I'm not that confident current capitalism is a final stage. Capitalism is a phoenix.]
So yes, of course there is no dobut that meds are being improperly prescribed to many children. And yes many diagnoses are almost certainly diagnoses of nothing. BUT, there is really no dubt that the condition named ADD is, for some proportion o fthose so diagnosed, a definite illnes, even a fatal one. At one clinic I know of, they as a matter of course x-ray each child brought to them said to be suffering fom "hyperactivity." Hyperactive kids (an earlier label for ADD) are prime targets of parental abuse. And yes, meds for these children are often of tremendous aid. So here the pharmaceucial corps are not inventing a diagnosis but 'merely' expanding its coverage beyond necessity, thus enlarging the market fo a drug that is indeed wonderful for those who really need it.
But "Of Course" really should be implicit in almost every sentence written on this topic. We are not talking about a separate or independent phenomenon generated within and/or by a particular group of corporate villains. We are simply talking about one manifestation of capital endlessly searching for new possiblities of growth.
Carrol