In the United States, the law says that a person must be at least 21 years old to drink alcohol. However, many people are tempted to drink while underage either from peer pressure or because of parents who drink. Regardless of the reason, statistics show that three out of every four teenagers in high school have experimented with alcohol. Many teens and young adults feel that alcohol won’t harm them or isn’t any more hazardous for them than it is for adults. But studies show that alcohol has more dangerous effects on adolescent brains than adult brains.

Alcohol Damages the Developing Brain

Alcohol adversely affects a teenager’s brain more than an adult brain because the adolescent brain is still developing. Alcohol can damage every brain, but for teenagers, the damage is more severe and can occur with smaller amounts of alcohol than with adults. For people in their early 20s and younger, there is an inverse relationship between the age of the person drinking alcohol and the damage that it does to their brain. This means that the younger a person is when they drink alcohol, the greater the damage from alcohol.

The average human brain continues to develop until the person reaches their early 20s. While the brain is developing, certain chemicals can do more damage than when the brain is fully developed. A good analogy is walking on concrete: Walking in wet concrete leaves footprints that remain after it is hardened. Walking on dry concrete won’t leave footprints. Alcohol acts much the same way on the adolescent brain, leaving more profound damage because it is still “hardening.” Adults whose brains are developed can also be permanently harmed by alcohol, but their brains can tolerate more drinking before permanent damage is done.

How Alcohol Causes Damage

Alcohol is classified as a depressant. Depressants negatively affect the central nervous system and slow down the brain. Teenagers will experience a greater loss of cognitive functions from its effects on the cerebral cortex. In short, alcohol diminishes the ability to process information. It also affects the brain’s frontal lobes, which govern decision-making skills, the ability to form ideas and inhibitions. This makes a teenager more vulnerable to impulsive actions, such as violent outbursts. It may also inhibit their ability to plan and think ahead.

The hippocampus is also affected by alcohol and this area governs memory retention. Excessive drinking can damage an adolescent’s short-term and long-term memory. Alcohol can also damage the cerebellum, leading to problems with balance, as well as the hypothalamus. Damage to the hypothalamus can be blamed for the increased need to urinate and lowered heart rate. The medulla is the section of the brain that regulates the body’s temperature. Alcohol causes the medulla to lower the body’s temperature and can lead to hypothermia. Excessive consumption of alcohol can kill brain cells in all of the above areas. As a result, alcohol can result in all of these problems becoming permanent. The amount of alcohol consumption that can cause permanent damage is much lower for adolescents than it is for adults. Studies show that brain damage can occur in teens who drink only half as much as the average adult.

Long-Term Effects of Alcohol Damage

Young adults who drink alcohol run a greater risk of serious and lifelong problems than adults who drink. These problems include poor impulse control, which leads to unsafe sexual activity and unexpected bouts of violence. Memory loss, poor retention of information and even blackouts are also more likely to affect someone who started drinking in their adolescent years. Problems with balance and the inability to walk straight may more readily become a permanent issue with young drinkers. Tests have shown that people who start drinking during their youth have problems doing simple tasks like reading maps or assembling objects. Teenage brains are also more vulnerable to developing an addiction to alcohol, also known as alcoholism. Alcoholism is more severe among teenagers, is harder to treat and addicted teens are more likely to have relapses. Studies show that up to 47 percent of those who start drinking alcohol before age 14 eventually become addicted.

While we know that excessive alcohol consumption can cause permanent damage to the human brain, what hasn’t been known until recently is why teenagers are more vulnerable. The teenage brain is still developing, which makes the effects of alcohol more likely to become permanent. Understanding this helps make it easier to see how adolescents are affected by alcohol consumption.

The following links include additional information about how alcohol affects the adolescent brain and the studies that were performed to measure its effects.