Early Drinkers May Make Risky Decisions Later in Life
Three weeks after receiving alcohol, some of the rats could choose between pushing a lever that always dispenses two sugar pellets or a second lever that will either dispense four treats or nothing at all. The researchers found that the rats who drank alcohol were more likely to choose the second, more risky option and the non-drinking rats made better decisions.
Nicholas Nasrallah, a UW psychology doctoral student and co-author of the study, said that while it is well known that early exposure to alcohol and drugs predicts later substance abuse, this can’t be tested on humans. Their animal study suggest a casual link between early alcohol consumption and later problems with decision making.
Corresponding author Ilene Bernstein, a UW professor of psychology, said that prior studies suggest that some areas of the brain, including those that are associated with decision making, develop in adolescence. This study found that these late-developing regions in rats are affected by heavy alcohol consumption, which suggests that they are also affected in humans.
Although rats don’t normally drink alcohol, the researchers found that they will consume it when mixed with gelatin. In the study, one group of rats that were 30 to 49 days old (which corresponds to human adolescence) was given free access to an alcohol gel (similar to a large number of alcoholic drinks in humans). Another group of rats was given a non-alcohol gel.
After 20 days, the gel was taken away from both groups. Three weeks later, half of the rats from each group were trained to press the levers to dispense the treats, which allowed the rats to experiment with both the “uncertain” and “certain” levers.
The alcohol-consuming rats showed a strong preference for the “uncertain” lever, but the non-drinking rats tended to stick with the “certain” lever, thus receiving more treats than the drinking rats.
The researchers conducted another experiment by testing the remaining rats three months after the gel was taken away, and found that the results were the same. This suggests that the effects of being exposed to alcohol during adolescents remain the same over time.
Bernstein said that adolescent drinking is an epidemic today, and this study suggests that since early alcohol exposure permanently changes the brain, more emphasis needs to be placed on educating adolescents and preventing them from abusing alcohol.
Source: Science Daily, Adolescent Alcohol Exposure May Lead To Long-Term Risky Decision Making, September 22, 2009