I've never imbibed--well, I know enough to know that I don't like the taste, but that's a small amount of champagne once at New Year's Eve, a sip of someone's homebrew once, and Communion wine once. (And, yes, at my church it was wine; I was an altar server, so I know.) It's the chemical substance alcohol that I don't like the taste of; the service mechanism doesn't much matter.
The problem with "drinking to feel better" is, in no small part, that alcohol is a depressive. The problem is that its first noticeable effect, as near as I can tell, is a release of inhibitions that, at first, makes you feel better. It's like drinking to stay warm--yes, at first you may feel warm, but its physiological effect is actually to cool you off.
"Social drinking" is drinking as part of a larger social function. The aforementioned glass of wine with dinner--actually, I'm okay with a drink of whatever you like even if you're having dinner alone, if you like the taste. I think problems start arising when you don't really care what it tastes like; you're drinking for the buzz.
I, of course, have never been drunk, but I do have a drunk uncle. (Well, I'm told he's recovering, but since I don't like him sober, either, I don't much care except for my cousins' sake.) I'd call him an alcoholic for several reasons, though of course I'm not qualified to make a diagnosis. First, he'd get roaring drunk at family gatherings, make everyone uncomfortable, and . . . well, I don't know what he'd do to my aunt and cousins when he got home, but I certainly wouldn't want to go with him. He would be told this was not okay. He would agree . . . and do it again next Thanksgiving or Christmas.
Second, he always had to be sure that there was alcohol at these gatherings. I remember vividly the Fourth of July that he brought two giant cans of Japanese beer--the kind where two cans is actually enough for an alcoholic for an evening. Or it would've been, if my little sister hadn't surreptitiously poured Coke in 'em whenever he wasn't looking. He wasn't that far gone.
Third isn't so much an alcoholic thing but a responsibility thing--he tried, repeatedly, to drive drunk. My aunt pretty much had to beg to get the keys away from him. The one time they were my ride anywhere, my older sister and I agreed we'd rather spend the night at Grandma's than ride with him driving. Mom'd get us in the morning, or Grandma or Grandpa would drop us off. (My little sister was sick on Christmas.)
But what we see here is a pattern of disruption that my uncle didn't see. That, too, is part of why I consider him an alcoholic.
"Now everyone was giving her that kind of look UFOlogists get when they suddenly say, 'Hey, if you shade your eyes you can see it is just a flock of geese after all.'"
"You can't erase icing."
"I can't believe it doesn't work! I found it on the internet, man!"