I'm extremely susceptible to alcoholism so I don't drink. There was a point when I realized I had no social phobia when I was drunk so I started taking every chance I could to drink with people so that feel better about not having a life (because I had one, not that that's any more of a life than I have now but you know what I mean) and also of course just to have fun.
Alcohol is an extremely slippery slope for me personally. I never want just a buzz, I want to get drunk. A couple beers seems totally pointless to me... but the drunker I get, the more I want to drink more. I'll be tipsy and thinking "OK just this one last shot, I'm already too wasted" and then "OK OK one more, this is the last one for real" and the more wasted I get the more I don't give a **** and the more I want more. Sure, it's great having no social anxiety, having confidence and having fun - but I hate everything else about who I am when I'm in that state, it's not me. After a night of heavy drinking, I wish I didn't remember the things that I do remember. All that applies for me when I'm just an occasional social drinker but being a social drinker led me to be a habitual drinker. I'd drink because I was depressed and I'd drink because I was bored. I spent about 6 months being drunk 4 to 7 nights a week and sometimes drank in the morning... sleeping problems, diarrhea, wasted money, and a continually degrading quality of life weren't for me, so I quit. I didn't cut back, I just quit. I'm fortunate it was so easy, I don't think I was a heavy/frequent drinker for a long enough period of time to develop the kind of dependence that real alcoholics do. I can't remember any major withdrawal symptoms other than the urge to get drunk. It's been two years.
I've read that people with Social Anxiety often self medicate with various recreational substances and it made me realize that I used smoking weed to cope for a few years even though it actually exacerbated my anxiety sometimes. It allowed me to be care free, relax and enjoy the company of a fun group of friends but also sometimes made me extremely paranoid and anxious around people and even by myself as I considered the possibility of running into someone or obsessively analyzed some recent social interaction. I've also done MDMA. On MDMA, I can't stand to be alone, I crave people to interact with and feel extremely lonely if I don't have them. I'm basically the opposite of my socially anxious self on MDMA, I turn into an extreme extrovert. Unlike when I'm drunk, I don't notice any negative changes to my personality on MDMA and I actually feel like it brings out some really great qualities in me so after my first experience I was very intrigued by the notion of using it for casual socializing with people who don't know I'm on it who maybe people who wouldn't approve (a very very bad idea, thank god I never did this)... but that stuff has an extremely high potential for abuse and when you abuse it, you'll regret it, so I've given that up too.
All of these substances that I've experienced using just alleviate some symptoms at best, they aren't a cure for the underlying psychological condition. Perhaps in moderation, you could enjoy that symptom relief in a somewhat responsible way, but although they alleviate some symptoms of SA, the side effects are just new symptoms you get in place their place just aren't worth it for me.