I just want to add the thought in, that with the advent of souls into DF, drugs (recreational and otherwise) might have a positive or negative effect on souls.
I read a report that compared the emotional/psychological state of well-being felt by habitual peyote users, compared to habitual alchohol users, and the report concluded that the peyote users tended to be much more well-adjusted and emotionally content, compared to the regular alchohol consumers.
I'm not saying it's so, and I'm not promoting drug use, kids--I'm just saying that's what I read, and it gave me some ideas (other than about getting high.).
So maybe in DF there can be a sort of drug "scale" that, in addition to whatever immediate effect a given drug may induce, could either harm or benefit the user's soul, in the long term. Possibly even healing emotional damage, at one end of the scale, or eventually destroying the user's soul, and rendering them into the "Living Dead" (a state of being as opposed to-but not far from-undead), or possibly even some form of demon, at the other end.
Ofcourse, a given drug could have more than one positive/negative effect, and ideally, any given drug would have a mixture of both.
Physical fatigue, short term insanity/severe hallucinations, etc. might still result from a drug that "healed" the user's soul, and a soul-destroying drug (in the long term) might still be used positively, as perhaps an analgesic (painkiller), while surgery was being performed.