Study examines behavioral changes that occur after a person heavily drinks as an adolescent

Adolescence is a time of change both physically and mentally. Many times it means trying new things and for some, that includes experimenting with alcohol.

It is estimated eight percent of the nation's eighth graders and 24 percent of tenth graders have been drunk sometime in their lives, according to the National Council on Alcohol and Drug Dependence. While there have been numerous studies into why adolescents drink, there has been limited research on the long-term effects of alcohol exposure in the development of young adults. But now researchers at Baylor University have just finished a three year study analyzing the behavioral changes that occur after a person heavily drinks as an adolescent.

Dr. Jamie Diaz-Granados, an associate professor and interim chair of the psychology and neuroscience department at Baylor, said the preliminary findings provide experimental results which support data showing that the earlier a person starts drinking, the greater the risk of alcohol addiction problems. In fact, he said the early onset of alcohol may even alter the development of the brain.

"The adolescent brain is in a state of flux," said Diaz-Granados. "Neurotransmitter levels are still being developed and synapses are still being formed. Alcohol affects virtually every single neurotransmitter in the brain, so the introduction of alcohol at an early age can have a profound impact."

Using rodent test subjects, researchers found the mice that were given high levels of alcohol during adolescence were more likely to seek out the drug later on. Even mice that became sick and developed a taste aversion to alcohol still sought out the drug after abstaining from it for weeks. Researchers said this was not the case with mice that were given alcohol during adulthood. Those mice also developed a taste aversion to alcohol and that stopped them from seeking out the drug again.

"It was the confirmatory piece of evidence that showed this was an issue of development," said Diaz-Granados. "It suggests that early exposure to alcohol somehow changes the reward pathway, so as an adult, alcohol is more rewarding than to those who did not drink as adolescents. That strong reward feeling can lead to alcohol abuse problems."

Funded by grant from the National Institute on Alcohol Abuse and Alcoholism, this type of research project exploring the long-term effects of heavy drinking is one of only a few completed in the nation. Researchers hope the findings will lay the groundwork for future studies that could analyze what physical parts of the brain are affected. Diaz-Granados also said it could one day lead to better pharmacological treatment. In the short term, this research could be used as an educational tool.

"If we can show children that this is what's happening to your brain, this is what's happening to your body if you drink alcohol at this age. They then can see they don't have control over it and that might stop some from drinking," he said.