Frank Zappa had a lot of other things that motivated him: the impetus of his art, Ambition, and I think he didn't have that itch.
He did an incredible spot about speed in the late 60s (paraphrasing), it's much better in the original): "Go ahead and do speed, it'll make you just like your parents." Obviously, it's on point when he does it. I think its on a radio show with Captain Beefheart,
But Zappa smoked almost as many cigs as Yul Brynner: 4- 5 packs a day. Leaving cigs smoking in various ashtrays when he was on set. I had a friend like that. He had to have a cig burning in every room. Got another friend like that at my age (40)

But original 5 cig guy is still alive and active and happy at 67. I have no idea why except he's got a real strong soul and he's active as hell. And he finally cut back to a pack a day.
On to drugs, I'm thinking about Billie Holliday, Dexter Gordon, Coltrane, Bird, Billy Strayhorn, Miles Davis, and Bill Evans in particular.
Oh, and as much as I revere Glenn Gould, he was on a crazy cocktail of pills, and painkillers and amphetamines figured strongly. Dude fought a very difficult fight to do what he did. He had crazy-ass OCD habits that may have been related to his depression/mental state and prescription drug use but he had a lot of unique and particular behaviors that he had to execute before performing. And they kept him off stage until he had performed all of his little OCD actions. But most of the time, he made it to the stage. But Glenn was not what we would nowadays consider clean.
I wish I could draw some conclusions, but I haven't figured it out yet. Wish I could. But I'm sure as hell trying to do so. What abut Billie Holliday, Ella, Sarah Vaughn, Hans Fallada and Bela Lugosi?
If you haven't watched the YouTube clip of Bela giving an interview right after he gets out of rehab, check it.
http://www.youtube.com/watch?v=EM88vyxN82k I hope that link works. I'm a bit clumsy with links on BL and I bet there's a better version of Bela. The clip's audio is dreadfully shoddy. It's beautiful though. He's the epitome of a compassionate, sensitive, gentleman junkie and his interview is really inspiring. Look at him giving love to all the nurses and doctors as he walks out the door of the clinic. Don't think Vampire Dracula whatever, he just looks like a casually well-dressed anybody like any of us when we get it together. Just throw it back several decades. Very inspiring for me.
tl;dr
But getting back to the OP's post, Ray Carver was a dude who kicked years of DT-level alcohol use and put a lot of energy into getting clean. Then he found a woman who kept him on track and became his muse and the one who kept him on track. She was his Gibralter. He started writing after he got clean, and "Cathedral" is just about the best anyone could write (Warning: triggers). He swears he couldn't have written anything good without being sober.
There's a really good story behind his process of getting clean. He had a rough family life and he cut all ties with everyone from his alcoholic past. His people were pissed, especially after he became successful. But he swears he'd never have written a word without cutting everyone off. He made a lot of enemies getting clean but he did what he had to do. Forget about Wikipedia giving you the full story about any of this, look into it if it resonates with you.
I'v got no conclusions. just a lot of stuff I think about regularly.