Put a stressed-out drinker in front of an exciting football game and he’ll forget his troubles. But put him in a quiet bar somewhere, all by himself and he’ll grow mare anxious. Alcohol's principal effect is to narrow our emotional and mental field of vision.
It causes, “a state of short- sightedness in which superficially understood, immediate aspects of experience have a disproportionate influence on behavior and emotion." Alcohol makes the thing in the foreground even more salient and the in the background disappear. That’s why drinking makes you think you are attractive when the world thinks otherwise: the alcohol removes the little constraining voice from the outside world that normally keeps our self-assessments in check. Drinking relaxes the man watching football because the game is front and center, and alcohol makes every secondary consideration fade away. But in a quiet bar his problems are front and center and every potentially comforting or mitigating thought recedes. Drunkenness is not disinhibition. Drunkenness is myopia.
But this article was more intriguing. Apparently drinking helps to reduce dissonance. In other words, you really can drink some troubles away.