What are long-term consequences of teen bullying behavior?

Teen bullying is often a warning sign that children and teens are heading for trouble and are at risk for serious violence.  Teens (particularly boys) who bully are more likely to engage in other antisocial/delinquent behavior (e.g., vandalism, shoplifting, truancy, and drug use) into adulthood.  They are four times more likely than nonbullies to be convicted of crimes by age 24, with 60% of bullies having at least one criminal conviction.

Taken from http://www.familyfirstaid.org/bullying.html