There's a pre-alpha Minecraft mod I read about that divided them into “spoons” (https://en.wikipedia.org/wiki/Spoon_theory), “brain worms” (e.g. depression, obsessive thoughts) and a generalised version of “special interests” (which models both the traditionally-ASD and traditionally-ADHD variants). It takes a very game-mechanical-as-applicable-to-Minecraft view of them, but I thought it was a decent framework. I'll see if I can find a link.
So if that paper is correct (and of course it is only one study, and we should have more studies to explore this question further), that suggests that maybe the distinction between ASD, ADHD and OCD ought to be abolished, and they all ought to be subsumed into one bigger disorder, that then might even be subdivided into a new set of subtypes (based on actual biology) which would have little in common with the existing ASD-ADHD-OCD distinction.