They are up 76% in girls aged 10-14, up 32% in girls aged 15-19, and up 9% in boys aged 15-19. It's the biggest spike in 15 years, the CDC's latest teen-suicide statistics show.

"This is a dramatic and huge increase" in pre-teen and teen suicide, Ileana Arias, PhD, director of the CDC's National Center for Injury Prevention and Control, said at a news conference. "We are seeing this increase in significantly younger Americans than we have seen in the past."

The data cover the year 2004, the latest year for which numbers are available. The CDC collects the information from death certificates. Because coroners and medical examiners don't always have enough information to conclude that a death was a suicide, the actual number of suicides is likely to be higher than the official number.

The new numbers reverse a decade-long downward trend in teen and youth suicide. It's too soon to know whether 2004 was an unusual year, or whether it marks the beginning of an upward trend. But the data suggest disturbing changes.

One disturbing change is the uptick in girls and young women committing suicide. The other disturbing change is that hanging or asphyxiation is becoming much more common -- particularly among 10- to 14-year-old girls.

The rate of suicide by hanging/asphyxiation more than doubled to 68 per 1,000 girls aged 10 to 14. Since 1990, when the CDC began keeping records, this rate was never higher than 35 per 1,000 girls in the same age group.

It's possible that this new trend toward hanging and asphyxiation is linked to a choking game that has recently become popular among schoolchildren.

As its name implies, the "game" usually involves using the hands, rope, or fabric to choke another child until he or she loses consciousness. The payoffs appear to be the brief "high" achieved during the loss and regain of oxygen to the brain, and the amusement derived from seeing a peer become disoriented.

As might be expected, this game has resulted in deaths. However, the CDC does not believe that a significant number of these deaths have been misclassified as suicides. It remains unclear whether the game is linked to the growing acceptability of hanging and asphyxiation as a suicide method.

The surge in teen suicide also coincides with a drop in antidepressant prescriptions for teens. This is due to concerns that the drugs may increase suicide risk for a subset of young people. Some psychiatrists feel this drop in prescribing is behind the surge in teen suicides, but Arias says this isn't the only issue involved.

"It is important to recognize that suicide is a multidimensional and complex problem. As much as we would like to attribute it to a single source, we cannot do that," she said. "So while antidepressant medication may have role in suicidal ideation, it not the only factor."

"It is possible that some subgroups of patients do become worse when given antidepressants, but the larger population benefits," Thomas Laughren, MD, head of the FDA's psychiatric products division, said at the news conference. "It is possible for two different things to be happening at the same time. We will continue to monitor suicide rates and antidepressant prescribing and take whatever regulatory steps are necessary."