Ethanol Consumption and the Developing Brain During Adolescence

Previous research on alcohol consumption has proven the negative effects it has on the human brain, especially during adolescence when the brain is in critical stages of development. Regardless of these findings, alcohol consumption during adolescence has been predominantly relevant for decades. This is often the outcome of influences such as environmental and social factors. For example, peer pressure is an influence that is often experienced during adolescence. Adolescence is a development stage that is characterized by the process of finding oneself in relation to themselves and amongst others. Peer pressure is a very prominent influence that can often lead to alcohol consumption and substance abuse because of one wanting to “fit in” amongst their peers. It is important to note that even the smallest amounts of alcohol consumption can tremendously affect teenager during their critical stage of development. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) states that alcohol consumption has shown to affect the neuropsychological performance of individuals which is characterized by the impairment of growth and integrity of various parts of the brain. Furthermore, NIAAA has stated an alteration of blood flow and electrical brain activity. Further research is crucial to better understand the development of the brain of adolescents. It is through such research by which not only can measures be effectively implemented to decrease the amount of underage alcohol consumption, but as well properly educate on the topic of alcohol consumption with scientific knowledge.

Jamie Donahey Roitmans’ study “Consequences of Adolescent Ethanol Consumption on Risk Preference and Orbitofrontal Cortex Encoding of Reward”  focuses on the changes in cortical encoding of rewards of different sizes and probabilities when alcohol is consumed by rats who were exposed to gelatin during adolescence. The electrophysiological activity of individual neurons in the orbitofrontal cortex was recorded during adulthood while rats performed a variety of risk tasks. At the beginning of Dr. Roitman’s talk, she explains some important areas of development the prefrontal cortex is involved in: physical development (i.e., reproductive maturity), and social development (i.e., sense of identity and relationships, independence in decision-making). These areas are vulnerable as they are in a phase of maturing. Going into the results, they showed how rats with high levels of alcohol consumption showed increased risk preference in the task versus the control group and the rats with low levels of consumed alcohol. Dr. Roitman also used the principal component analysis to observe patterns of neurons in which results suggested lasting effects on reward processing when making decisions for the high alcohol consumption group. Moreover, the differences in the orbitofrontal cortex of high alcohol consumers from the control group support the proposal from the study that “voluntary consumption of alcohol during adolescence biases choice patterns longitudinally through alterations in cortical function.” This is important to note as the orbitofrontal cortex is a crucial region involved in encoding or rewards and goal-directed decision-making. Because of these alterations in the hypofrontality, the study suggests that alcohol consumption in adolescents can increase risk for psychiatric disorders, including depression. Another interesting finding in Dr. Roitman’s research is that significantly higher levels of ethanol consumption is not necessary for persistent effects on higher level cognitive abilities (i.e., risk preference). These findings are interesting and very useful in learning more about adolescence and alcohol consumption, particularly the effects on their risky behaviors and neurophysiology.

An article titled, “How Alcohol Ravages the Teen Brain,” by Janet Hopson was published two years ago on the Scientific American. The article is composed of various studies proving the long-term effects of alcohol consumption among adolescents. Similar to Dr. Roitmans’ work, its findings showcased that alcohol consumption can damage parts of the maturing brain and produce long term deficits. The article has the same conclusion on long-term effects, but focuses on learning and memory in people rather than solely on risky behaviors and reward. One of the studies in the article, which was conducted at Wayne State University, tested the inhibitory control skills of twelve to fourteen-year-old teenagers while they were in an MRI machine. After taking MRI scans, the researchers tracked the teens for at leasts four years and focused on their alcohol consumption over time. The teens who began to drink heavily during this time showed less activation than those who abstained in 12 brain regions, including areas from the prefrontal cortex and the parietal cortex which help to produce planned movements. As stated in the article, these findings show that the circuitry responsible for inhibiting an action is not operating quite perfectly. Compared to Dr. Roitmans’ research, this study proved an alteration in the brain before consuming alcohol which is interesting in itself but still useful in learning about the neurophysiology and risky behaviors of adolescents, as it led to a risky behavior of alcohol consumption during teenage years. It is interesting to note that the study used MRI scans to identify alterations in brain regions, rather than the principal component analysis and electrophysiological activity. This study is useful in helping help target at-risk teens before they transition into a heavier binge drinking lifestyle.

Another important finding mentioned in the article by Janet Hopson is from the work done by Fulton Crews. Fulton Crews’ work showed that a high blood alcohol level in rats kills cells in the brain’s frontal lobes and hippocampus. These are crucial components for memory formation. This finding can be relatable to binge drinking in humans. In relation to adolescent alcohol consumption, the study mentions how the adolescent rates are more sensitive than adults to this consequence. Therefore, smaller doses of binge drinking can lead to the same damage in these areas. The method in analyzing blood flow changes is slightly mentioned in Dr. Roitman’s study as well. Although this research found damage to different areas of the brain and had a different method, the study can relate to Dr. Roitman’s research as they both come to the general conclusion of alterations in the brain due to alcohol consumption in adolescents. Furthermore, the alterations lead to deficits in cognitive abilities.

Lastly, another important study to note is one that is mentioned in the article by Janet Hopson. This study involves a team at the University of South Carolina that found significant alterations on spatial working memory. The study involved a group of non-drinkers and heavy drinkers in their teens that were asked to recall shapes and perform various spatial working-memory tasks. Findings of the study found that when looking at the nondrinkers group and the one to two year heavy drinking group, both groups were able to perform the same in exercise but there was a significant difference in the activation of their parietal cortex. The heavy drinkers group were found to have a more active parietal cortex. When looking at the group of three to four years heavy drinking group, performance on the tasks were worse and there was a decline in activity in their parietal cortex and other brain regions involved in vision and motor control. The study shows how the brain tries to keep up which only results in increasing levels of activation in brain regions. It is important to note that the brain could only compensate for so long and when such point is reached the brain can’t keep up and performance drops as seen among the three to four years heavy drinking group. Unlike Dr. Roitmans’ study, the study done at the University of South Carolina involved a method that was comprised evaluating performance tasks. Regardless, both studies found that alcohol consumption during adolescence greatly impacts various brain regions.

Overall, it can be seen throughout the studies that alcohol consumption during adolescence can heavily impact multiple regions of the brain. Dr. Roitman’s found significant findings in risk preference and rewards of rats, affecting the prefrontal cortex - mainly the orbitofrontal cortex. In the Scientific American article, various studies are mentioned including: the study at Wayne State University that showed significant alterations in the inhibitory control skills and changes in activation of the prefrontal cortex and parietal cortex using MRI scans, the study done at the University of North Carolina that found alcohol consumption leading to high blood alcohol levels in rats result in damage of the brain’s frontal lobes and hippocampus, and the study done at the University of South Carolina that found significant alterations on spatial working memory overtime from heavy drinking. All of these studies found significant changes in brain regions when looking at alcohol consumption during young adulthood. These findings prove that the brain during adolescence is not fully matured. It is important to continue researching the effects of alcohol consumption during adolescence in order to keep providing scientific knowledge for educational purposes in the context of alcohol prevention. As a result of such efforts, not only would significant alterations to an adolescent’s brain be prevented but the quality of life would greatly increase as well.

Cited Works:

Hopson, Janet. (2016). How Alcohol Ravages the Teen Brain. Retrieved December 11, 2018 from https://www.scientificamerican.com/article/how-alcohol-ravages-the-teen-brain/

Mcmurray, M. S., Amodeo, L. R., & Roitman, J. D. (2015). Consequences of Adolescent Ethanol Consumption on Risk Preference and Orbitofrontal Cortex Encoding of Reward. Neuropsychopharmacology.

National Institute on Alcohol Abuse and Alcoholism (NIAAA). Underage drinking: Why do adolescents drink, what are the risks, and how can underage drinking be prevented?  Available at: 
http://pubs.niaaa.nih.gov/publications/AA67/AA67.htm.