The final segment of the series focuses on how alcohol and drugs affect the adolescent brain’s reward system.
Finding ways to satisfy needs and desires is part of life. It’s one of the many skills that is being fine-tuned during the teen years. When a teen takes drugs, it can interfere with her/his natural ability to feel good. Here’s how drugs affect the brain.
The brain is made up of billions of nerve cells. Nerves control everything, from when her/his heart beats to what she/he feels, thinks and does. They do this by sending electrical signals throughout the body. The signals get passed from nerve to nerve by chemical messengers called neurotransmitters.
For example, some of the signals that neurotransmitters send cause a feeling of satisfaction or pleasure. These natural rewards are the body’s way of making sure we look for more of what makes us feel good. (For instance, when we eat something tasty, neurotransmitters tell us we feel good. Seeking more of this pleasure helps to ensure we don’t starve.) The main neurotransmitter of the “feel-good” message is called dopamine.
All drugs of abuse overload the body with dopamine—in other words, they cause the reward system to send too many feel-good signals. In response, the body’s brain systems try to right the balance by letting fewer of the feel-good signals through. As time goes on, the body needs more of the drug to feel the same high as before. This effect is known as tolerance.
The effects of drugs on the brain don’t just end when the high wears off. When a person stops taking a drug, their dopamine levels are low for some time. They may feel down, or flat, and unable to feel the normal pleasures in life, even when meeting a basic life need. Their brain will eventually restore the dopamine balance by itself, but it takes time—anywhere from hours, to days, or even months, depending on the drug, the length and amount of abuse and the person.
Because they have an overactive impulse to seek pleasure and less ability to consider the consequences, teens are especially vulnerable when it comes to the temptations of drugs and alcohol. And because the internal reward systems are still being developed, a teen’s ability to bounce back to normal after abusing drugs may be compromised due to how drugs affect the brain.
For more information visit www.drugfree.org or www.drugabuse.gov.