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Drugs & Health Blog

Sculpting Your Brain: The Science of Addiction

Images of Brain Development in Healthy Children and Teens (Ages 5-20)

The NIDA Blog Team

You make a lot of important choices in your teen years. Some of them can’t be unmade, and can have an impact on your life for years to come. 

One of those choices may be about using drugs. It’s an important choice because, for starters, using drugs can affect the way your brain develops.

Crucial connections

We’ve described how your “brain circuits” coordinate everything you feel, think, and do. These circuits are formed by billions of neurons (nerve cells) that are connected to one another. When you think or do something, messages are sent across the connections, or synapses, between neurons.

In healthy brain development, synapses that are used over and over grow stronger, and synapses that aren’t used much get weaker. This process is called “synaptic pruning.”

In a way, your brain gets smaller—fewer connections between brain cells means less “gray matter”—but the connections that are left are more efficient.

That may sound a little weird, but it’s normal. See the brain images above, which show a healthy brain developing from ages 5 to 20. In both the side view and top view of the brain, the reduction in gray matter—due to unused synapses—is shown by yellow turning to blue.

New skills—and risks

Images like this taught scientists that a person’s brain changes dramatically from childhood through young adulthood. Those changes may be strongly influenced by your experiences during that time, including the choices you make. Those choices and actions can “shape” your brain, like an artist creating a sculpture by chipping away marble.

The easily sculpted brain in the teen years helps you do things like develop language skills or understand new concepts—but the process can also reinforce thinking and behavior that doesn’t help you.

This may be one reason that the earlier a person begins using drugs, the more likely the person is to develop a drug problem, including addiction. That’s why we say addiction is a brain disease.

The brain still changes even when you’re an adult; it may be that nothing is “hard wired” permanently. But the earlier you learn to do something, the more “strongly wired” that behavior is, and the harder it is to unlearn it later.

Before you choose to use drugs, remember that the possible consequences for your brain can last a very long time.

Are there effective treatments for drug addiction? Find out here.

Comments posted to the Drugs & Health Blog are from the general public and may contain inaccurate information. They do not represent the views of NIDA or any other federal government entity.


I thought that the above image was used to teach about brain myelination with less yellow representing greater myelination. Please let me know if this is correct or not. If not, then I need to remove this from my training slides.

The imaging technique “simply” renders level of neuronal density in a color gradient from high (yellow) to low (blue). The reduction in neuronal density through maturation reflect in part the process of neuronal pruning.

This has made me not want to do drugs anymore after reading this article

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