Drugs!

Drug use in fiction frequently falls into the trap I blog about here, and that John Seavey also discusses: Taking our culture as a template for something much more exotic.
I’ve seen an astonishing number of settings—parallel world, far future, decadent, exotic—where the standards for acceptable drug use mirror ours (“our” referring to USA within my lifespan) to a laughable degree. People smoke cigarettes (or some comparable substitute). They drink booze and caffeine. They may use pot. And everything else is Bad Drugs.
John Ostrander and Tim Truman’s Grimjack, for example, is set in a decadent, corrupt city at the center of infinity—but for all the alienness, everyone still smokes and drinks. Other drugs, when they come up in stories, are Bad (I only read a couple of years before finances forced me to drop it, so I can’t state that as an absolute fact for the entire run [and the same team’s Hawkworld did indeed show a culture where drug use was routine]).
The truth is there’s an astonishing amount of drugs out there, and even in our own history, we haven’t always held the same views. Cocaine and LSD were legal at one time; someone from the 1940s would be astonished to see all the places where cigarettes aren’t legal any more (SF from 70 years ago seemed to take it as a given that no matter how far we go into the future, people will still smoke).
So it’s surely no great strain to assume that some other culture might have legal LSD or consider opium an acceptable and unremarkable recreational drug. Or maybe something alien to us that’s as addictive as nicotine but just as socially sanctioned (well, as socially sanctioned as when I was a kid).