Science has known for some time that people who have fewer negative side effects from drinking tend to drink more and are at a greater risk of developing alcoholism. The problem is, no one was really sure why some people were less affected by alcohol. That is, until now.
Scientists have now discovered the region of the brain that controls sensitivity to negative effects. This is the area that helps people learn from mistakes. The brain region, called the lateral habenula only activates during bad experiences.
To test how the lateral habenula was affected by drinking, scientists deactivated that portion of the brain in rats. The rats were then given a supply of alcohol and monitored. The result was that rats without a working lateral habenula would drink far more than the rats with a full working brain.
"In people, escalation of intake is what eventually separates a social drinker from someone who becomes an alcoholic. These rats drink amounts that are quite substantial. Legally they would be drunk if they were driving," said Sharif Taha, a professor of neurobiology and anatomy at University of Utah.
The learning from negative experiences created by the lateral habenula can be seen in everyday life. Many people have eating something which gave them food poisoning and, once well, developed a dislike for the thing that made them sick. The same can be true for certain drinks. Many people develop an aversion to a particular type of alcohol after a negative experience drinking too much.
The co-author of the research, Andrew Haack said, The way I look at it is the rewarding effects of drinking alcohol compete with the aversive effects." By taking the negative effects away by deactivating the lateral habenula, the researchers were able to create rats that only saw the good side of drinking. That means the rewards associated with alcohol far outweighed the sacrifices.
While this new research is not, in itself, a total explanation for alcoholism, it does go a long way to helping people understand what causes some people to drink to excess while others are easily able to moderate their consumption.
With this knowledge science may be able to provide prior warning to people at risk of developing alcoholism, develop treatments for those who abuse alcohol and help people better understand their relationship with drinking.
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