Alcohol and Its Impact on the Brain

What You Need


  • Newsprint and markers
Alcohol and Its Impact on the Brain Photo Credit: Clipart.com.


To help students understand how alcohol affects different parts of the brain, which in turn affects behavior.


This lesson is part of a series created by Science NetLinks as part of The Science Inside Alcohol Project, funded by the National Institute on Alcohol Abuse and Alcoholism (NIAAA). For a complete list of materials, visit The Science Inside Alcohol: Educational Materials. The project has developed an e-book for students and four accompanying lesson plans that teach middle-school students about how alcohol affects the human body.

This lesson was produced under Grant #1R25AA016107-01A1, NIAAA.

Alcohol is by far the most abused drug of the teenage years. In a 2009 study sponsored by the National Institute on Drug Abuse (NIDA), 14.9% of eighth graders, 30.4% of tenth graders, and 43.5% of twelfth graders admitted to drinking alcohol in the past 30 days.

Previous lessons have focused on the short- and long-term effects that alcohol has on the mind and body; how risky behavior that can result from drinking can affect-and harm-other people; and how alcohol affects the digestive system, the central nervous system, the circulatory system, and the endocrine system. This lesson hones in on the impact alcohol has on the brain and the central nervous system, what behaviors result from alcohol use and abuse, and what alcoholism is and the changes in the brain that occur to result in this condition.

In the Motivation, students answer seven questions designed to find out what they know about alcohol and its effect on the brain. Their responses serve as a pre-assessment to the lesson. After students complete the lesson, they will be asked to revisit these questions as a way to determine what they have learned.

During the Development, students are presented with a scenario about two peers who have started drinking heavily. The students' task is to develop an argument convincing their friends why it is in their best interest to stop drinking and to come up with a presentation explaining their ideas. Students may work individually or in pairs in developing their arguments, and they can use whatever media they would like to present them. The argument can be written up and presented orally, done as a PowerPoint presentation, or explained through illustrations. After discussing the arguments, students will consider which arguments were most convincing and why.     

Ideas in this lesson are also related to concepts found in the following alcohol learning goals:

  • The brain is the body's control center, managing every move all of us make. Alcohol affects the way the brain functions, causing short-term and potentially long-term changes.
  • Different parts of the brain are affected by alcohol in different ways. Some of these impacts are life threatening.
  • A person becomes addicted to alcohol when his or her brain adjusts to the way alcohol alters the brain so that drinking becomes necessary in order to function.


Planning Ahead

To provide you with sufficient background to teach this lesson, you can visit The Science Inside Alcohol Project, which includes additional educational material. You can also read Delaying That First Drink: A Parents' Guide for the latest research on the impact of alcohol on the growing body and tips on how to talk to kids about drinking.


Begin the lesson by handing out the Questions to Think About student sheet. Give students about 10 minutes to answer the questions. Tell them not to worry if they do not know all the answers. Explain that they will learn about these topics during the lesson.       

Once students have gone through the student sheet, hold a class discussion to go over the questions and answers.

  • What are some of the first effects of drinking alcohol?
      (Often the first effects are that people become more relaxed and sociable, a byproduct of the fact that alcohol decreases inhibition.)
  • Why do people who drink too much sometimes forget what happened?
      (Alcohol can interfere with the brain's recording of memories.)
  • Why do people sometimes pass out from drinking too much alcohol?
      (A person may pass out from drinking too much alcohol when it reaches high levels in the Reticular Activating System, or RAS. The RAS is the part of the brainstem and midbrain that controls whether you are awake or asleep. Alcohol levels quickly reach equilibrium throughout the brain. Different brain regions have different levels of sensitivity to alcohol. Some are affected by very low levels of alcohol, while others require higher levels of exposure.)
  • Why is it dangerous to drink too much alcohol too quickly?
      (Someone who drinks too much alcohol too quickly is at risk for passing out. This happens if the midbrain shuts down. A common misconception about passing out is that it is a protective mechanism against negative consequences. This is not necessarily the case. Even after passing out, blood alcohol levels can continue to rise, causing respiratory depression and possibly even death. Another danger is that sometimes people pass out and then end up vomiting—and can choke on their vomit and suffocate if no one is around to help them. Therefore, it is critical that teenagers and young adults realize that passing out is serious. Anyone who passes out should be watched carefully until they wake up.)
  • How does drinking too much alcohol affect behavior?
      (Alcohol can cause young people to make bad decisions; take risks they would not usually take, such as drinking and driving or having unprotected sex; and engage in heavy drinking as a result of increased tolerance and the need to drink more to get the same effects as before.)
  • What are the signs that someone is developing a problem with alcohol?
      (Signs that indicate that individuals are developing a problem with alcohol include the need to drink more to get the same effects they had previously, a sign of the development of tolerance to alcohol. Also, these individuals tend to be less affected by alcohol than others—that is, they tend to be able to "hold their liquor." Finally, looking for opportunities to drink becomes an important part of their life and begins to take over other activities.)
  • What does it mean to be addicted to alcohol?
      (A person who is addicted to alcohol, referred to as an alcoholic, has become so dependent on alcohol that the brain starts to adjust to the way that alcohol slows it down. As a result, the brain gets too excited without alcohol and needs its slowing effects in order to function properly. Some alcoholics may have trouble starting the day without a drink.)
  • Are young people who begin drinking before the age of 21 more likely to become alcohol dependent?
      (Research points to a relationship between early onset of drinking and later alcohol-related problems. Consider these facts: In 2003, the average age of first use of alcohol was about 14, compared to about 17½ in 1965. Those individuals who reported starting to drink before the age of 15 were four times more likely to also report meeting the criteria for alcohol dependence at some point in their lives. New research suggests that the serious drinking problems [including what is called alcoholism] typically associated with middle age actually begin to appear much earlier, during young adulthood and even adolescence. [Alcohol Alert: Underage Drinking, January 2006, National Institute on Alcohol Abuse and Alcoholism. Available at: http://pubs.niaaa.nih.gov/publications/aa67/aa67.htm].)


In this part of the lesson, students will learn more about how alcohol affects the brain by studying a resource made especially for them and by developing an argument to convince two students to stop drinking.

To begin, students should use their Alcohol and Its Impact on the Brain student esheet to go to and read the Alcohol and Your Brain student resource. Tell students that this resource explains how alcohol affects the brain and the central nervous system, resulting in potentially dangerous behaviors.

Once students have finished reading the resource, discuss these questions with them:

  • Why is the CNS particularly vulnerable to the effects of alcohol?
      (Alcohol can pass through the blood-brain barrier, reaching neurons directly. Once alcohol touches these cells, they are changed, resulting in changes in behavior.)
  • Name three indicators that point to the fact that the brain is slowing down as a result of alcohol use.
      (Three indicators are: altered speech, hazy thinking, and foggy memory.)
  • What impact does alcohol have on the cerebellum? The medulla?
      (The cerebellum is the part of the brain that helps control movement, balance, and complex motor functions. Alcohol can decrease motor function and slow reaction time so that a person has trouble standing up or walking in a straight line. The medulla is in the hindbrain and controls heartbeats, breathing, and other functions. During periods of heavy drinking, these functions may slow or stop working altogether, endangering a person's life.)
  • What behaviors do teens sometimes engage in while drinking?
      (While drinking, teens' ability to reason and weigh choices may become impaired, and they may engage in risky behaviors, such as unprotected sex or drinking and driving. Alcohol also may interfere with prescription drugs that some teens take. For example, alcohol mixed with Ritalin may damage a teen's ability to perform tasks that require total concentration. Large amounts of alcohol mixed with lithium may result in poor judgment, impaired thinking, and difficulty performing motor functions, such as driving or even walking.)
  • What is new research saying about binge drinking and brain development?
      (Dr. Susan Tapert of the University of California, San Diego, compared MRI brain images of binge drinkers and non-binge drinkers. She found a difference in the quality of the white matter. She then tested the teens to find out how this difference affected functioning. She found different results for girls and boys. For girls, their ability to complete spatial tasks, such as completing a complex puzzle, was affected. For boys, it was their ability to pay attention. Researchers are now investigating whether these effects are permanent or resolve themselves over time.)

Present the class with the scenario on the How Alcohol Abuse Begins teacher sheet. You can copy this sheet onto a transparency and use an overhead projector to show it to students or you can make copies and distribute the sheet to students. Tell students that their assignment is to develop an argument to convince Carlos and Claudia to stop drinking. Students should include information about the different parts of the brain and what each one does; how alcohol affects the brain and changes behavior; and the serious consequences of excessive drinking. Students can work by themselves or in pairs for this assignment.

After students develop their arguments, give them additional time to design a presentation explaining their ideas. The presentations can take the form of a PowerPoint slide show, a video, a poster display, or simply a written report. Students will probably need to finish their presentations as homework.

To learn more about the effect of alcohol on the brain, students can refer to the resources listed on the Alcohol and Its Impact on the Brain student esheet.

Over the next couple of classes, make sure that all students have a chance to present their findings. Then discuss similarities and differences among the different arguments. What tone do students think is most effective with their peers? Is a visual presentation more powerful than a verbal one? What information should be included in the argument?


As students present their arguments to the class, consider the following:

  • Do students seem comfortable with the subject matter?
  • Have they absorbed the information?
  • Have students picked relevant information to include in their arguments? Are they able to focus on the most important pieces of information? Have they used this information to develop a strong argument?
  • Have students considered the most effective way to make a strong argument? What strategies have they used?

Ask students if they have some questions about alcohol use that they would like to see addressed in future lessons. Write down their ideas on a sheet of newsprint and use it as a resource when planning additional lessons.  

At the end of the lesson, pass out a blank copy of the Questions to Think About student sheet, which has the questions students answered at the beginning of the lesson. Ask them to answer them again. Students' second round of answers is also an indication of how much they have learned during this lesson.

Finally, to help students "stay with the program," have them involve their parents or caregivers. To inform parents/caregivers about students' work on this topic, consider using the Letter to Parents and Other Caregivers.


After learning about the effects of alcohol on the brain, suggest that students develop a "No Drinking" campaign at school. For information, they can use this lesson and any others in the series they have worked on. Students can write brochures, develop a public service announcement for the school, or sponsor an assembly on the topic.  

In addition, you could lead students through these other Science NetLinks lessons related to alcohol:

Did you find this resource helpful?

Lesson Details

Grades Themes Project 2061 Benchmarks National Science Standards