From what I've learned, adolescents are at a higher risk for addiction/other problems including growth problems because they are still maturing (going through puberty). Also, if they start drinking a considerable amount consistently starting from an early age, they can start to experience some of the symptoms of alcoholism earlier in life (slurred speech, disorganized thought process, etc.)
I hope this helps! I think you should check in with another source, though, too. :)