I was a drinker in high school and I would say the main effect is "doing really stupid things." Those things tend to make you upset later on, and even depressed too. Geez, one time I set fire to my parent's porch, microwaved our welcome mat, and ran around wearing only a folded pizza box--in the same night. I thought it was pretty funny at the time, and for a decent while afterward. However, I think that I could have found other ways to be funny at that age instead, without engaging in behaviors that were questionable or destructive. So, my thought is this: Discourage the drinking because of x,y, and z reasons which we all know about. BUT, also encourage other fun outlets for the young adults. Even the edgy, questionable ones. Geez, everyone has to get into some trouble during their youth just to get it out of their system. I would be fifty times happier if my son got in trouble for doing some silly prank that got him in trouble with neighbors, strangers, or even the police, than if he was getting into substances and doing stupid stuff and didn't even get in trouble.