Adolescent Brain Development


Between the ages of 15 and 25 more young people die from accidents of almost every kind than at any other stage of life. Most long-term drug and alcohol abuse starts during adolescence. And, to anyone who hasn’t studied the brain, adolescent behavior can be perplexing and frustrating.

Why is this?

The short answer, the brain is not yet fully developed. Not only is the brain not fully developed, from ages 12-25, the adolescent brain enters a period of heightened neuroplasticity when the brain is pruning and strengthening its internal connections. This is a period of enhanced opportunity but great risk. You can liken it to opening a window. If the air is fresh it can be quite good for you. However, if the pollution level is high, say a truck is revving its engines just outside, it can be quite toxic. Or, compare it to concrete work. When the concrete is wet, even heavy rain drops can destroy the work. However, when the concrete is dry, you can do quite a bit to it before ever doing any damage.

If you are wondering why you have not heard this, the understanding is new and still developing. We used to think the brain was pretty much fully developed by about five. And, that this period of heightened neuroplasticity only existed from birth to about three. Hence, the big focus on Birth-Three and Young Einstein programming. Now, advances in science tell us differently.

As a parent what you need to know and share is that not only is the teen brain still developing, it works differently than a fully developed adult brain and is actually susceptible to negative consequences not seen in a fully developed adult brain. Every person goes through this developmental period starting about 12 and ending in the 20’s. It doesn’t matter if your teen is smarter than you, taller than you, has a full beard or seems to think and make decisions more rationally than you. Their brain is indeed developing.

Since it is not possible to share all of this new understanding on our website, some important facts are listed below along with some recommended reading for those that want to know more.


  1. The region of the brain responsible for decision making, impulse control and goal setting (the frontal lobe) is still developing in your child through high school and beyond. This is particularly problematic because this is the same area first affected by alcohol. In other words, when a teen uses, they are further impairing an area that is already underdeveloped, causing them to make decisions that can carry negative consequences for a lifetime.
  2. Brain cells are not fully myelinated (protected) causing slower processing and longer lasting impacts. This can have multiple consequences not seen in adults. For starters, it makes it hard for teens to make good decisions in the moment. That is why it is so important to preplan with your teen. And, the impacts are different and more lasting. An adult that uses marijuana will have cognitive impairment for a few hours. A teen could experience cognitive affects that last up to a week.
  3. The base rate of dopamine, a feel good neuro-chemical, is low for teens. This means they get bored easily. However, the amount of dopamine released when a teen experiences almost everything (music, drugs, sweets…) is far greater than found in an adult. The good news, when things feel good, we tend to remember them more. That is one of the reasons why adolescents are able to learn and retain information about three times better than adults and our strongest memories are often from the adolescent years. The bad news: this results in an enhanced susceptibility to addiction. A teen can develop a full blown addiction to alcohol in a matter of months where it would take an adult with a fully developed brain years to develop one.

The below books can help further your understanding and are available at both the Bloomington and Normal Public Libraries.

  • You and Your Adolescent: The Essential Guide for Ages 10-25  Laurence Steinberg, Ph.D

 This book is reminiscent of the “What to Expect When You Are Expecting” and “What to Expect the First Year” style of writing. Only this book looks at adolescent development and walks you through what is happening physically, behaviors you can normally expect to see during each stage of development and offers suggestions for how to best support your adolescent through all of it.

  • The Teenage Brain: A Neuroscientist’s Survival Guide to raising Adolescents and Young Adults Frances Jensen, MD, with Emily Ellis Nutt

This book takes a look at what is happening developmentally in the brain and is presented in an interesting and practical way. It is filled with scientifically backed insights on how learning and multitasking, stress and memory, sleep, addiction and decision making are different for those going through Adolescence.

  • Brainstorm: The Power and Purpose of the Teenage Brain Dr. Daniel Siegel

This book helps to reinforce the new messaging that we are working to get out to teens through the UNSTOPPABLE campaign. It provides insights into the brain development taking place during the teen years and helps dispel some common myths about adolescence.