(*Binge-drinking teenage tearaway rats make bad decisions in adulthood)
Experiments in rats show that alcohol abuse in adolescence affected the animal’s decision-making in adulthood, leading them to make poorer decisions and take more risks, according to research by Bernstein and colleagues from the University of Washington and published online on the 21st September in the journal PNAS.
Alcohol abuse, and in particular teenage binge-drinking, is becoming a serious and chronic health epidemic. Cheap alcohol is readily available and we don’t know the long term consequences from alcohol abuse at an early age. The European School Survey Project on Alcohol and others Drugs (ESPAD) is an extensive international study looking at teenagers’ drinking, smoking and drug-taking in 32 countries across Europe. Results from the 2007 survey ranked the UK 3rd in the binge-drinking European league; there were higher than average scores in variables including alcohol use and drunkenness in the last 12 months (88% of teenagers had consumed alcohol and 57% had been drunk in the same period) and the estimated alcohol consumption from the latest drinking day (6.2 cl alc. 100%, much higher than the European average of 4.2). Previous studies in humans have shown that young binge-drinkers had impairments in decision-making and that excessive alcohol intake may have an affect on the development of a young brain. There are somewhat obvious ethical issues in getting kids drunk and seeing what the long-term effects are so researchers used rats to investigate the direct link between alcohol consumption in adolescence and decision making as an adult.
The researchers fed adolescent rats a tasty gel containing 10% alcohol, or a control alcohol-free gel, for
20 days. In adulthood, either 3 weeks or 3 months after alcohol exposure, the rats were trained on a food reward task to measure their decision-making abilities. They were offered the choice of two levers; one gave a small but guaranteed reward of two treats, the other gave a larger, but uncertain, reward of four treats occurring 75%, 50% or 25% of the time. The control teetotal rats chose the small but more consistent rewards whilst the rat binge-drinkers were significantly more likely to make riskier choices and pick the larger but uncertain reward under all conditions.
These findings provide evidence that alcohol abuse in adolescence can lead to impaired decision-making as an adult. Furthermore, these effects persisted for at least 3 months after alcohol exposure. The model can be used in future experiments to understand just how alcohol exposure during adolescence affects the brain. This research suggests that alcohol abuse in adolescence could permanently change the way the brain works and that strategies to prevent teenage binge-drinking should be promoted.