Chess on drugs discourse

There was actually a 2017 study examining the effects of Caffeine, Ritalin, and Provigil on club-level players. All three of the substances had the same pro and the same con. The pro is that all three increased the amount of time that players spent thinking about moves, and so theoretically made the players think deeper. The con was that, because of this, the experimental group tended to lose more games- they would just run out of time. With no clock involved, the Ritalin and Provigil (not the Caffeine interestingly) resulted in significant improvement, but with the clock involved, all three hurt more than they helped.

Source: "Methylphenidate, modafinil, and caffeine for cognitive enhancement in chess: A double-blind, randomised controlled trial"

A bit exclusionary towards neurodivergence, and dismissive of the deficits people experience.
Counter-question: For everyone who gets prescribed medication for chronic conditions, undermining their ability to focus and pay attention, are all their opponents cheating when they play unmedicated? Is that baseline itself, not a significant advantage for only one (neurotypical) player?

Everyone has physical and mental attributes that variably help or hinder them in different endeavors. In sports and games fair play does not consist of removing these advantages or hinderences (not that such a thing could be realistically done, outside a few rare exceptions), but in assuring that competitors do not used prohibited methods or substances. Prohibited substances usually being those that provide an advantage, but also cause harm. That is, competitors should not feel the need to harm themselves in order to play well.