Zagamezza, I am an addiction specialist with 30 years experience in the field. I have treated adolescent alcoholics/addicts as well as adults. I also keep up with the current scientific research published in reputable journals and books. Here is what I've learned from experience as a doctor and my ongoing education.
1. The earlier one begins drinking/using alcohol or drugs regularly the greater the chance that one will develop an addiction. Only a few years makes a large difference: someone who begins drinking regularly at age 13 is much more likely to become addicted than someone who begins regular drinking at age 18.
2. An adolescent who drinks to cope with feelings is far more likely to become alcoholic/addicted that one who drinks to "fit in" socially. This is because adolescents who drink to "fit in" eventually realize when they get older that they dont need others' approval.
3. The more relatives an adolescent has that are alcoholic or addicted, the greater the probability they will become addicted if they use substances regularly. This does not imply that people without such relatives cannot become addicted.
4. The more an adolescent assumes adult responsibilities (job, parent, citizen, church member, etc.,) as he/she grows-up the less chance he/she has of becoming alcoholic/addict in adulthood even if they are using substances heavily in adolescence. This is because adult responsibilities are inconsistent with using.
Hope this helps. EP