New brain research on adolescents has shown that although teens may look like adults and try to act like them, the area of the brain that regulates emotions and impulses is still developing, and the systems aren’t yet completely connected.

“Biology doesn’t make teens rebellious or have purple hair or take drugs,” says Jay Giedd, a neuroscientist at the National Institute of Mental Health (NIMH) and a leader in this emerging field. “It does not mean you’re going to do drugs, but it gives you more of a chance to do that.”

Such findings may explain the blank teenage expression that so often follows those “What were you thinking?” moments.

But it also should give parents — and society — pause as they struggle with the question of how much freedom and responsibility teens can handle. Are they children in adult-like bodies or very nearly adults?

It’s not that simple, says Ronald Dahl, a professor of psychiatry, pediatrics and psychology at the University of Pittsburgh, where adolescent brain research has been particularly prolific. He says that even though adolescents can appear to reach adult levels of thinking, in some situations they are more vulnerable to impulsivity.

“If you take a kid who has lots of social support and self-discipline and is making good decisions, he is not necessarily going to go out and do crazy things,” Dahl says. “But put him in an environment that activates strong feelings and thrills, and it gets more complicated.” …

Researchers have found the prefrontal cortex, which regulates impulse and emotions, develops later than originally thought — well past age 18 and likely into the mid-20s.

Despite more work, Richard Lerner, director of the Institute for Applied Research in Youth Development at Tufts University in Medford, Mass., says adolescent brain research is “still in its infancy.” …

Earlier views were incomplete: “The newer thinking is the notion of more and more of the brain involved in the decision-making,” Giedd says. “We overlooked probably a more important part, which is this integrating and pulling together of all the brain parts.” …

Parents have a role

The study found that when kids showed resistance to peer pressure, the prefrontal cortex thickened, and areas of the brain showed more connections. Lerner says this illustrates an association between brain function and structure and resistance to peer influence. The association was clearer among girls than boys, but there were no gender differences in resistance to peer influence, he says.

“The issue is, which comes first,” Lerner says. “Can we enhance connections by training on resistance to peer influence or can we find other ways to stimulate the brain to be more connected?”

In his book The Good Teen, to be published in November, Lerner says teens are not inherently difficult or disproportionately emotionally troubled.

“The problem is that parents are often not playing the role of parent,” he says. “Often parents want to be the friend of their adolescents. Teenagers need adults to mentor them, coach them and guide them…”

Source: USA Today
http://www.usatoday.com/news/health/2007-09-26-teen-freedom_N.htm