Beer-guzzling teenagers may be setting themselves up for a lifetime of anxiety or alcohol dependence.
Binge drinking -- which 15 percent of high school students say they do, according to the Centers for Disease Control and Prevention -- could affect brain development and behavior in adulthood, according to a study published March 23 in the journal Neurobiology of Disease.
Researchers at the University of Illinois at Chicago found that pounding down drinks during adolescence may disrupt gene expression and brain development, possibly contributing to behavioral changes in adulthood.
"Binge-drinking has a profound effect... on brain development and neuronal connectivity," Subhash Pandey, a neuroscientist at the university and the study's lead author, wrote in an email to The Huffington Post. "This effect is long-lasting and thereby alters the adult behavior."
Specifically, the researchers found that binge drinking -- which for men is defined as drinking five or more drinks in a two-hour period, and for women as four or more drinks in that same time period -- may cause genetic changes that are linked with anxiety and alcohol dependence in adulthood.
Scientists have long known that teens who binge on booze are at an increased risk for alcoholism and psychiatric disorders down the road, but this new study helps explain why, the study's authors said.
For the experiment, the researchers observed the behavior of rats who had been given alcohol when they were young. They saw that the rats were much more likely than a control group to exhibit anxiety and a preference for alcohol in adulthood.
Subsequent analysis of the rats' brain tissue revealed DNA abnormalities in the amygdala, a small brain region associated with decision-making, emotional reactions and memory.
The researchers explained that changes they observed in the epigenome -- chemical compounds that modify the way the genes express themselves -- seem to impair communication between neurons in the brain.
“These findings are an important contribution to our understanding of the alcohol-induced brain changes that make alcohol problems in adulthood more likely among young people who abuse alcohol,” National Institute on Alcohol Abuse and Alcoholism Director George F. Koob said.