How Alcohol Changes the Adolescent Brain

Oct 01, 2020
By Alexander Gómez-A

Although the elevator has been out-of-order for about one-week, Alex, 28, continues standing in front of it, pressing the button, and waiting for it to arrive. Then, after some time, he remembers that the elevator is not working and use the stairs. Why did this happen to Alex? Was he a distracted person? Or was he not paying attention to the signs? Maybe he has memory issues? The reason might be any of these (or others). But, this is not the first time Alex has been confused in his daily life. The question is, why? We could find part of the answer in Alex’s history. During adolescence, Alex drank alcohol on weekends and usually, he would drink until he became drunk. He also remembers several episodes of blacking out during  those “crazy weekends.” The pattern of how Alex drank as a teenager  is commonly known as “binge-drinking.” 

Scientists define binge-drinking as the consumption of large amounts of alcohol in short periods of time. Since binge-drinking is common among adolescents, and the adolescent brain is still maturing, an interesting question has emerged in the scientific community: What are the effects of binge-drinking on adolescent brain development? We know that alcohol changes the adolescent brain and that some of those changes can be permanent. For example, a properly developed brain usually helps us to adapt ourselves to changes in our environment. In other words, we can modify our behavior according to our needs. Underage drinking, however, affects that flexibility, making us persist in actions that are not necessarily appropriate for what we need (remember Alex and the out-of-order elevator). 

Let us look at what underage drinking changes in our brains. As you may know, our brain is composed of small cells called neurons, which communicate with each other in a very organized fashion. Neurons convey information that is critical for a specific (or multiple) function(s), for example, hearing. Likewise, groups of neurons in diverse regions of our brain work together to support all the body’s vital actions (e.g., heartbeat or breathing) as well as the complex psychological functions that make us different from other species, like thinking, learning, and memory. 

What alcohol does is change how communication happens by decreasing the number of neurons supporting the aforementioned functions. It also can change the “internal machinery” of neurons and, as a result, the way those neurons work. So, it is easy to conclude that, after alcohol affects millions of cells in our brain, the various functions that the cells support will also be affected. Let me give you an example. We know now that adolescent alcohol consumption decreases the number of acetylcholine neurons. This type of neuron is involved in numerous cognitive processes. So, if we put together the facts that, alcohol affects acetylcholine cells, and that acetylcholine cells are involved in cognitive functions, we conclude that alcohol has the potential to influence cognitive processing.  

Scientists have observed this in studies over the last few years. Adults (animals and humans) exposed to alcohol during their adolescence are more susceptible to difficulties in some cognitive processes. For example, they have a hard time preventing responses that were no longer useful under some circumstances. They were also less flexible in shifting to a new and more adequate response. Although our example of Alex’s behavior at the elevator was a simple situation, the way alcohol induces changes in our brain can make us more susceptible to real and very complicated issues like a substance use disorder. 

Although this sounds hard to fix, some harmful alcohol effects can be prevented or even reversed by introducing changes in lifestyle, including healthy food, exercise, and cognitive stimulation. In some studies done with animals, exercise reverted the decrease in acetylcholine neurons caused by adolescent alcohol consumption. Hence, although alcohol induces changes in the way how the adolescent brain develops, avoiding alcohol consumption and maintaining a healthy lifestyle will keep you away from Alex’s behaviors. Wait, was it Alex or Alix…? Never mind!

Edited by Emma Goldberg and Anna Wheless