For the first time, researchers have shown in an animal model how heavy alcohol use can cause long-term brain damage that affects decision-making.
In a new study published in Science Advances, scientists found that rats exposed to high levels of alcohol had lasting cognitive problems, even after being alcohol-free for months.
The study was led by neuroscientists from Johns Hopkins University. They wanted to better understand how alcohol damages the brain and affects behavior.
“We know people with alcohol addiction often struggle with learning and decision-making,” said Patricia Janak, one of the study’s authors. “This new animal model helps explain what might be happening in the brain.”
In the study, rats were exposed to large amounts of alcohol for one month. Afterward, they went through a withdrawal period lasting almost three months. Then the rats were tested with a complex task that measured decision-making.
In the task, the rats had to choose between two levers to earn a reward. One lever had a higher chance of giving a reward than the other. To make the task harder, the researchers frequently switched which lever was better. Success required the rats to quickly notice these changes and adjust their choices.
While healthy rats quickly adapted, the alcohol-exposed rats performed much worse. They were slower to adjust and earned fewer rewards. “The alcohol-exposed rats just couldn’t keep up,” said Janak. “The control rats figured things out faster and were more strategic.”
When the researchers examined the rats’ brains, they found that the alcohol-exposed rats had major changes in a brain region called the dorsomedial striatum.
This area is important for decision-making. In the alcohol-exposed rats, the brain signals used for decision-making were weaker and less effective. This suggests that alcohol had damaged the brain circuits needed to process information and make good decisions.
One of the most surprising findings was how long the effects lasted. Even after three months without alcohol, the rats still showed signs of impaired thinking. This may help explain why relapse is so common in people recovering from alcohol addiction.
“Even after rehab, some people may still have brain damage that affects their choices,” said Janak. “This could be one reason why staying sober is so hard.”
The study also found that these long-term effects were only seen in male rats. The researchers don’t believe this means female rats are immune, but that there may be differences in how alcohol affects male and female brains over time.
The team plans to study how other parts of the brain interact with the dorsomedial striatum and what might be causing the sex-based differences.
If you care about alcoholism, please read studies that your age may decide whether alcohol is good or bad for you, and people over 40 need to prevent dangerous alcohol/drug interactions.
For more information about alcohol, please see recent studies about moderate alcohol drinking linked to high blood pressure, and results showing this drug combo shows promise for treating alcoholism.
The study is published in Science Advances.
Copyright © 2025 Knowridge Science Report. All rights reserved.
