In the post you linked, I saw something I didn’t realize — that in clinical trials, they test drugs like this on known adult addicts to see the impact. (Quote: “given intravenously to adults with histories of stimulant abuse.”) At first blush I had some concern about that, but the reality probably is that (a) they’re already in trouble and (b) there’s no alternative way to test the potential problems the drug could cause in the real world. Still, I would hope that they wouldn’t pay people who are in recovery to participate in such trials. Active users, I can live with. I would hope that’d be an acceptable pool.