Adolescent brains run with raw emotions

How alcohol damages young people's brains

Give yourself the edge, let yourself get drunk, tip you behind the bandage ... in German usage there are numerous paraphrases for getting drunk with alcohol. What sounds funny can, however, have negative long-term consequences. Because excessive alcohol consumption can seriously disrupt the brain development of adolescents and young adults.

Image: angelhell / istockphoto.com

The boy in the blue track jacket was just lying motionless on the floor. Suddenly he flies through the air as if by magic, does a back somersault and lands on his bike. It quickly becomes clear: the film is running backwards here. Lukas drank a lot of alcohol in the “Hausparty” commercial and then tried to ride a bike with 1.3 per mille. Binge drinking, as the “Know your limit” campaign conveys, can end badly. Unlike in the film, life cannot be rewound if it goes wrong.

Asynchronous development

The problem with alcohol is that it reduces the ability to react and the ability to coordinate and at the same time increases the willingness to take risks. This effect is even more pronounced in young people than in adults. Why?

From the point of view of brain research, the likelihood of binge drinking increases in adolescents because the limbic system and the prefrontal cortex develop asynchronously, i.e. with a delay. The limbic system is located between the cerebrum and the brain stem and is responsible for processing emotions. The “rewarding” effect of alcohol has its origin here.

The opposite pole is the prefrontal cortex. Reason reigns here, which puts the instinctual impulse from the depths of the brain in its place. In adolescents, however, the prefrontal cortex is not yet fully developed, while the limbic system is already doing its work at full throttle. The result: the consequences of one's own actions are only insufficiently weighed. For short-term fun, the risks are simply hidden.

Brain development by the age of 25

But binge drinking is poison for the brain and can have a lasting effect on the development of gray cells. Contrary to what was previously assumed, brain development is not completed in childhood, but continues until around the age of around 25.

In childhood, the focus is on the development of gray matter. This is the outermost cerebral cortex, also known as the cortex. Adolescence is another phase of the restructuring. Interconnections between the brain areas are established and refined. An important process in this maturation phase is the myelination of nerve fibers. The so-called myelin sheath forms a kind of insulation layer, which ensures the trouble-free transmission of electrical nerve impulses. Because the myelin sheath is white, this area of ​​the brain is also known as white matter. However, heavy binge drinking can affect white matter development.

Brain structure changed by binge drinking

The American researcher Susan Tapert and her team were able to show that changes in white matter caused by binge drinking can already be detected in 16 to 19-year-old adolescents. For comparison, young people of the same age who had never been intoxicated but were comparable with regard to their level of education and other factors were used.

With the help of a special imaging method, diffusion tensor imaging (DTI), the young people were thoroughly x-rayed so that even the smallest deviations in the structure of the white matter could be detected. The results show that adolescents have more pronounced changes in white matter the more often they have had a hangover from alcohol.

Hippocampus is affected

Studies using high-resolution magnetic resonance imaging have shown that a region known as the hippocampus is particularly affected. There are two hippocampi in the brain - one on the left, one on the right - and in adolescents who drink alcohol intensely, at least one of them is significantly reduced in size. What follows from this?

The hippocampus makes a decisive contribution to the fact that information is transferred from short-term to long-term memory, in other words: So that we really remember what we have learned. If the function of the hippocampus is impaired, memory problems arise. What has just been learned is soon forgotten.

Serious effects such as Korsakov's syndrome are only to be expected after years of alcohol abuse, but memory deficits can also be determined in adolescents if one compares the performance of adolescent heavy drinkers with those of adolescents who are abstinent.

A UK research team has checked this. In the study, the young people involved first had to assess for themselves how often they forget things in everyday life that they actually intended to do, such as meeting friends. They were then shown a video of a shopping trip. Before that, they had a few minutes to memorize a few tasks that were linked to certain scenes in the video film. For example, they should remember to text a friend when the film protagonists enter a certain store.

There were no differences with regard to the self-assessment of the young people. In contrast, however, were the test results. The adolescents drinking noticed significantly less in the video. "The heavy drinkers remembered up to a third fewer tasks," says research director Thomas Heffernan. Studies also indicate that it sometimes takes years of abstinence before the brain returns to normal, age-appropriate performance levels.

Acute tolerance

Animal experiments also indicate that the adolescent brain may develop more slowly due to alcohol consumption. In a laboratory test, the researchers Elena Varlinskaya and Linda Spear examined how teenage rats react to an injection of alcohol. It was observed that the juvenile rodents were not as anesthetized as adult animals and that they exhibited fewer motor impairments. In addition, the young rats lacked any obvious signs of alcohol intoxication. What sounds good at first, but has to be bought at a high price.

The cause of what the authors of the study call “acute tolerance” is a kind of compensation mechanism. The rats' brains try to make up for the impairments caused by alcohol by adapting quickly. But the effort that the brain has to make for this is to the detriment of the general development of the brain. In short: adolescents can tolerate alcohol better, but pay for it with slowed brain development.

Conclusion

Recent scientific studies have shown that binge drinking is detrimental to brain development in young people. In particular, damage to the hippocampus could be detected, a region that is important for memory formation.

Even the well-known blackouts - memory gaps after heavy drinking - can be seen as a warning sign of impending damage to the hippocampus. Because here the alcohol apparently led to a short-term failure of storage in long-term memory. What was yesterday evening has simply been lost in the intoxication.

It may take several years of abstinence to return to a reasonably normal level of performance. But studies also show that those who get used to getting drunk for fun as adolescents are more likely to develop an alcohol problem later.

Swell:

  • Bava, S. & Tapert, S. F. (2010). Adolescent Brain Development and the Risk for Alcohol and Other Drug Problems. Neuropsychol Rev, 20 (4), 398-413.
  • Heffernan, T., Clark, R., Bartholomew, J., Ling, J. & Stephens, S. (2010). Does binge drinking in teenagers affect their everyday prospective memory? Drug and Alcohol Dependence, 109 (1-3), 73-78.
  • Hermens, D. F., Lagopoulos, J., Tobias-Webb, J., De Regt, T., Dore, G., Juckes, L., Latt, N. & Hickie, I. B. (2013). Pathways to alcohol-induced brain impairment in young people: A review. Cortex, 49, 3-17.
  • Lee, H., Roh, S. & Kim, D. J. (2009). Alcohol-Induced Blackout. Int J Environ Res Public Health, 6 (11), 2783-2792.
  • Lubman et al. (2008). Substance use and the adolescent brain: A toxic combination? Journal of Psychopharmcology, 21 (8), 792-794.
  • Medina et al. (2007). Effects of Alcohol and Combined Marijuana and Alcohol Use During Adolescence on Hippocampal Volume and Asymmetry. Neurotoxicol Teratol., 29 (1), 141-152.
  • Varlinskaya, E. & Spear, L.P. (2006). Ontogeny of Acute Tolerance to Ethanol-Induced Social Inhibition in Sprague-Dawley Rats. Alcohol Clin Exp Res, 30 (11), 1833-1844.