Adolescent boys who have very low self-esteem at age 11 and have friends who approve of alcohol and other drug use are more likely to become dependent on illicit drugs by the time they reach their 20th birthday, according to researchers from Florida State University.

"Low self-esteem is kind of the spark plug for self-destructive behaviors, and drug use is one of these," said study co-author John Taylor. "It's a fundamental need to have a good sense of self. Without it, people may become pathologically unhappy with themselves, and that can lead to some very serious problems."

Researchers looked at data on 872 boys collected over a span of nine years and concluded that those with very low self-esteem were 1.6 times more likely to be drug dependent at age 20 than their peers.

"The fact that you can identify a group of people who are at risk for problematic behaviors is very important," Taylor said. "If you can intervene on a group of people before they begin drug use or embark on a cycle of addiction, that could have huge health benefits."

The study was published in the Journal of Child and Adolescent Substance Abuse.