Kingsley Amis shares a little banal insight into the artistic life: "[L]et me just observe in passing that the reason why so many professional artists drink a lot is not necessarily very much to do with the artistic temperament, etc. It is simply that they can afford to, because they can normally take a large part of a day off to deal with the ravages." Kingsley Amis, Everyday Drinking.
I have little doubt that's true, but I also have little doubt that there is something about the artistic temerament that leads to such excess, at least among the non-genius artists. I tend to view alcohol and drugs for the artist as a kind of artifiical door to perception. In this, perhaps my outlook is skewed by Aldous Huxley and Jim Morrison. I mean, most of us have been drunk, but how many of us can claim to some super-charged mode of creative existence in such states? When I'm drunk, I claim a super-charged mode of creative TV remote control manipulation, but that's about, and even that charge of activity normally gives way to another viewing of Caddyshack or GoodFellas and snoring.
I also don't think marijuana gives rise to much creativity. I've been around a lot of stoners. The most creative they get is finding new ways to open a bag of Doritos. And acid? Forget it. When Cheech takes that handful of acid at the beginning of Up in Smoke, Chong doesn't say, "Get ready to write a novel," but instead, "Ho, ho, ho, ho. Wow man. . . . I hope you're not busy for about a month."
But then again, we have the example of Roger Miller, who wrote a lot of great stuff while piped on cocaine. He kicked the addiciton and, the story says, never wrote another decent song. There's also Jack Kerouac's On the Road, which he cranked out while on Benzedrine, but whereas Ian Fleming's James Bond took Benzedrine I could find no reference that Fleming himself did. Poe, Marion Montgomery assures us, drank liquor, but while he wrote? I can't bring myself to pay $50 for Montgomery's book, so I might never know.
So, bottom line? I don't have one. Just a few educated guesses: A moderate amount of alcohol opens up the creativity; excess kills it. Marijuana and acid kills it. Bennies and cocaine? A moderate amount fuels the physical component necessary to create (a guy can't write while asleep), but doesn't contribute much to the creative element, except perhaps in a handful like Roger Miller.