"Round No. 5!" a girl shouts, holding a half-empty bottle of cheap vodka in one hand and a shot glass in the other. "Who's up for round five?"

It's Friday night and a few dozen college students are crammed into a small house a few blocks from the University of Mary Washington.

The party is well under way, as evidenced by the growing number of empty beer cans and the quickly dwindling liquor supply.

Binge drinking is an all too common feature of college life. Approximately 44 percent of college students are classified as heavy or "binge" drinkers, according to the Harvard School of Public Health's College Alcohol Study.

There is not a clear consensus on just what constitutes binge drinking. Some, like the Harvard researchers, use a 5/4 rule--five or more drinks at a time for men and four or more for women is considered binge drinking. Others say binge drinking is based on reaching a blood alcohol level (BAC) of 0.08.

Students have their own take.

"It's drinking a lot in one night," University of Mary Washington junior John Rowlay said. "Maybe more than eight or nine beers at a time."

"It's past the point of being wasted," said Danielle Deville, a UMW freshman. "Like if you drink so much that you pass out."

Regardless of the definition, experts agree that binge drinking is a problem.

NOT JUST A HANGOVER

Binge drinking can cause a laundry list of long-term health problems, from decreased bone strength to heart and liver disease.

"It is an insidious process," said Dr. W. Ronald Gaertner, an addictionologist with Insight Psychiatry in Fredericksburg and Richmond. "Long-term effects don't show up until decades later. But, the pattern is set."

Dr. Paul Riley, director of student health and the university physician at Mary Washington, said many in the medical field classify alcohol as a neurotoxin, to which younger brains are more susceptible.

Heavy drinking in adolescence and young adulthood can damage the hippocampus, the part of the brain that controls memory, and the prefrontal area, which is involved with decision making.

The young adult brain is undergoing rapid changes, so drinking can have adverse long-term effects, the the American Medical Association says.

DANGEROUS RISKS