As a teenager myself, I agree that bullying creates many detrimental effects that can last in the future. Personally, I haven't been picked on yet in high school. I believe it's due to the social circle that the individual is in where they may be a target for bullies. One of the many mistakes people make in their teen years is attempting to fit in with people who will in the end, back stab them.
Examples include: Physical bullying, Verbal abuse, Racism, Discrimination, Talking behind their backs etc.
I don't know about you guys, but I personally just hang around people who have the same interests as me eg. (Sport: Basketball) and that's all we do.
From what I've seen personally, people who have groups SITTING AROUND and just TALKING during their lunch breaks are the ones who are most likely to get bullied. Face it ; It just gives people more excuses to talk behind their friends backs. Hanging around with the right type of people and I can almost guarantee you that bullying will be rare.
For teens, the only advice I can really give for victims is : Don't try to fit in with people who you know are going to victimize you.
Other contributing factors include where the individuals live and the rates of bullying among locations.
As for adults: I don't know.. Honestly, I can't imagine adults that would still continue their reign of bullying, but society would probably take care of something like that.