Binge drinking at an early age can have lasting effects, a new study finds. Even if discontinued, it increases the risk of developing anxiety later in life, according to researchers at the University of Illinois at Chicago.
“Binge drinking early in life modifies the brain and changes connectivity in the brain, especially in the amygdala, which is involved in emotional regulation and anxiety,” said Subhash Pandey, the lead author of the study, in a statement. Pandey is a professor of psychiatry and director of the Center for Research in Alcohol Epigenetics at UIC.
As the brain develops, it undergoes chemical changes to DNA, RNA or specific proteins associated with chromosomes that change the activity of genes. These epigenetic changes are required for normal development of the brain, but they can be modified in response to environmental or social factors, such as alcohol or stress.
In the study, researchers exposed adolescent rats to a regimen designed to mimic binge drinking. “In humans, this is targeting seniors in high school through college,” said Pandey. “That is a crucial time for brain development.”
Researchers found that rats exposed to binge drinking exhibited anxious behavior later in life, even if the binge drinking regimen stopped in late adolescence and the rats were able to mature into adulthood without additional alcohol exposure.
“When the developing brain is exposed to alcohol it causes long-lasting epigenetic reprogramming and that is more dangerous to the brain,” said Pandey. “It makes the brain more vulnerable to stressful conditions.”
Rats that had been exposed to binge drinking had lower levels of a specific protein in the amygdala, called Arc, that’s responsible for the normal development of synaptic connections in the brain. Rats with less Arc also had about 40 percent fewer neuronal connections in the amygdala compared with rats that weren’t exposed to alcohol. Researchers believe these changes were caused by adolescent exposure to alcohol.
“The biological changes that occur are long lasting and may be responsible for psychiatric disorders,” said Pandey, who recently completed a study that yielded similar findings in humans.
In that study, researchers found people who began drinking heavily before age 21 also had lower levels of Arc, compared to those who began drinking heavily after the age of 21.
“This suggests that the developing brain is very susceptible to damage caused by alcohol exposure,” Pandey said.
Evan Kyzar and Huaibo Zhang of the University of Illinois at Chicago are co-authors on the paper.