Related to this Q it's pretty easy to confirm from the meme the part that claim that Leon Eisenberg said what he said about ADHD, using e.g. his Wikipedia page where Der Spiegel is given as source for the quote.
On the other hand, is he the "inventor" or "scientific father" of ADHD, which is another part of the meme? (The longer white-on-black text uses a different phrase than title on yellow background.)
His role in establishing the disease in the DSM for example isn't at all clear from Wikipedia. So what research did he conduct on ADHD or on what DSM committees was he to justify the claim that he was the inventor in some sense? [His Wikipedia bio is extremely long, with tons of publications listed etc., which suggests the page is a job by huge fan-- e.g. it also also says he is 'known as "the father of prevention science in psychiatry"', but doesn't explain what role (if any) he may have played in establishing ADHD in the psychiatric nosology.]
FWTW, a bit more googling on this, found an auto-biographical claim of Eisenberg from 2007, namely that he and Michael Rutter pushed for the inclusion in DSM II:
Mike Rutter and I participated in a World Health Organization Seminar on Diagnosis and Classification in Child Psychiatry in 1967. We had to argue vigorously for the inclusion of hyperkinesis as a syndrome (Rutter et al 1969). Other participants were highly skeptical about the frequency with which the diagnosis of hyperkinesis was used in the United States. Most U.K. psychiatrists allocated the symptom complex to the category ‘behavior disorder’. We won the debate. In consequence, hyperkinetic reaction of childhood appeared as a category in DSM II in 1968. It was not, however, until DSM III (1980) that attention-deficit/hyperactivity disorder (ADHD) entered the official lexicon.
This part is probably closer to an answer, but checking Rutter's bio on Wikipedia, it's also not very illuminating (but it's much shorter than Eisenberg's). I'm slightly skeptical however that a debate at a WHO seminar settled a DSM debate even in 1968, given how US psychiatry is/was parochial enough to have its own manual/classification. Are there third-party sources that confirm Rutter and Eisenberg's importance in the establishment of ADHD or at least of hyperkinesis in DSM II?
The 1969 paper he cites has some 300+ citations in Google Scholar, but IMHO this is pretty low for it to be a seminal paper in a field like psychiatry. (The paper itself turns out to be a report on the seminar, of sorts.) There are newer papers with thousand of citations, in one journal alone [that makes it easy to rank them]. A concrete example from the same sub-field would be this paper about ADD with and without hyperactivity, which has 700+ citations in GS. The related paper which they cite as seminal to this distinction has some 1000+ GS citations. (Speaking of which, ADD variant without the H was a distinct DSM-III addition that Eisenberg doesn't seem to claim to have contributed to.) Or, ahem, this history paper with some 800 citations in GS, which alas doesn't say who pushed for hyperactivity to be included in DSM-II, although it covers some earlier descriptions of perhaps similar syndromes to a great extent.
In fact the [1969] 22-page paper has about two paragraphs about hyperkientic syndrome as such because the seminar discussed all of the psychiatric nosology of then. It cites no other papers for that section and is written in an impersonal style...
It was suggested that there was a need for a category such as "hyperkinetic syndrome" [...]
There was general agreement that such a syndrome was often encountered by child psychiatrists and it was decided that the category of "hyperkinetic syndrome" was needed and should be included in the classification scheme. [...] On the whole, most participants felt that "hyperkinetic disorder" should be classified as a sub-category of "developmental disorder" as there were many similarities with the other conditions under this general heading. Only further clinical experience and further research would determine whether ultimately this was the right place to include it.
So, yeah, the official record doesn't help too much here. Also "the classification scheme" really refers to the ICD there (in its envisioned 1975 revision) as the intro to the paper/seminar makes clear. Who was in charge of DSM-II [1968] and how they were convinced is slightly less straightforward.