Lately, it seems no one can agree on how to treat teenagers with depression. Some doctors think the condition is under-diagnosed and needs to be treated more aggressively, while others worry about studies showing that antidepressants increase the risk of a child committing suicide. According to Jeffrey Hunt, a clinical associate professor of psychiatry and human behavior at Brown Medical School, the confusion is especially rampant when it comes to treating adolescents with bipolar disorder, or so-called manic depression.

"There's still a host of unanswered questions," Hunt says. Even though about 750,00 U.S. children and teenagers live with the illness, "we don't yet have a consensus as to what we're talking about when we say bipolar."

But in a landmark study in the February Archives of General Psychiatry, Hunt, along with lead author Martin Keller (who is chairman of the Department of Psychiatry and Human Behavior) and several colleagues helped shed light on what bipolar means. They found that adolescents go through more mood swings in a shorter amount of time than grown-ups do. Teenagers even switch back and forth between mild types of manic depression and more extreme forms more often than was previously thought. Hunt believes that adolescents with manic depression may have it worse than older people, which is one reason the illness leads to more suicides among juveniles than do other types of emotional disorders.

Hunt concludes that doctors need to be more aggressive in treating bipolar teens. But he also says his colleagues need to be especially careful that their patients are truly manic depressive, and not just in the throes of teenage moodiness and irritability. "Drugs for bipolar disorder can lead to weight gain and diabetes," he says. "If they are truly not needed, you are creating a problem where there never was one."