Hollywood hasn't had a single cocaine epoch, but an ongoing, never-ending love affair with the drug–one among many–since there has been a Hollywood. Drug abuse in the film industry actually predates Hollywood's establishment as the center of the American film industry in 1915; it is foundational, practically a found thing.
Cocaine was as common as aspirin and major stars blew their fortunes on thousand-dollar-a-week cocaine habits. ~ The Cokey Comedies of the Silent Screen Era
Alta Centers, a L.A. based addiction recovery facility, suggests the ubiquity of drug abuse in Hollywood is due to the unique pressures of being a celebrity. I think that's playing a little too much to the home crowd. It seems to have more to do with how creative people are generally more susceptible to mood disorders and depression, conditions for which drugs may be seen as an antidote, if not the antidote. To say nothing of the general debauchery great wealth and prestige tend to engender.
Even accounting for Hollywood's history of drug abuse, the 70s and 80s were a period of unfettered excess. The Blues Brothers famously had a cocaine budget for night shoots. But it wasn't just The Blues Brothers–it was every movie, everywhere, all at once. Rob Lowe compared the ease of getting cocaine to craft services providing Red Vines. Dennis Quaid said it was baked into the movie's budget and people would do a line of coke in lieu of a cocktail.
Cocaine usage in the U.S. peaked in 1982, the same year Return of the Jedi was filmed. I’m not suggesting George Lucas was snorting blow. I’m just saying a lot of people were, including, famously, Princess Leia herself. (There is a running joke about Carrie Fisher’s clearly-visible coke nail in Return of the Jedi, but she later said she only used dollar bills or tiny spoons.) Harrison Ford, her scruffy-looking co-star, had a coke habit at the time. I couldn't find definitive proof Mark Hamill was snorting coke, but he certainly looks like he's on something.
I recently rewatched Return of the Jedi, ostensibly because it's celebrating its 40th(!) anniversary. Though I've seen it enough times to commit it to memory, I was struck by just how bizarre most of the movie is. Tonally, it's completely different than the two that proceded it.
Drugs would certainly explain some of the gonzo stuff that ended up in Return of the Jedi. If I’m George Lucas and the choice is between claiming I intentionally created some of this — on purpose — and admitting drugs were involved, I’m probably going with the latter option to save face. Then again, this is the guy who thought Jar Jar was a good idea.
Let's review the evidence.