I've only known a couple of smokers who weren't depressed for about six weeks or so after they quit. I have to think it's coming off the nicotine as much as anything.
I think I'll just avoid that whole scene by not getting hooked on the coffin nails to start with. There are just no positives to being addicted to them. It's bad for you on every level. I don't fuss at smokers, but I do wish they would give up the habit. It's getting too expensive, if nothing else! Wow, but those things are pricey.