Understanding Teen Brain Development: Insights From Health Experts

As children make the transition from childhood to the teen years, everything changes. Their bodies grow during puberty, their voices change in pitch, and they get their first taste of independence. While these changes are apparent, changes within their brains are slightly more subtle. A teen's brain undergoes significant rewiring during this growth phase, from emotional input to decision-making.

As teens face new insecurities, find new ways to be confident, and are forced to make bigger life decisions, their brain development reflects that. We speak with an expert in neurological and brain development to see exactly what happens when this dramatic change occurs.

How the Brain Transitions From Child to Teen

As a child's body develops, so does the brain. The changes we can't see happen between the ages of 10 and 13. This is when the most significant growth occurs and when parents may notice their children's moods and interests shift. A child's way of thinking is often black-and-white, with little wiggle room. Their curiosity is piqued, and they constantly question things in their pursuit of answers. Their decision-making skills are quick, and they often answer without a second thought.

As their brains shift into teenhood, changes in the brain cause them to see the world more mutably. Their decisions grow to include a gray area, and they might become more impulsive in their choices. Dr. Nicholas Schmidlkofer, DC, DACNB, is the Clinic Director at The Neurologic Wellness Institute explains the chemical reasoning behind this.

“The brain undergoes significant structural changes as a child enters teenagehood. The most significant change is a reduction in brain cells, with an increased focus on the connections those brain cells make among each other,” he says.

“These connections are strengthened with a fatty substance called myelin that helps to insulate the electrical signals for smooth transmission. At the same time, the unnecessary connections or synapses between brain cells are removed through a process called synaptic pruning. The reduction of brain cells and synapses and an increase in myelin continue throughout the teenage years.”

How Do These Chemical Reactions Influence Decisions?

As these chemical changes occur in the brain, a child's frontal lobe begins its long period of growth. This part of the brain can continue growing until age 20, which is why the teenage years are so formative. During this time, preteens can still see the “big picture” in their decision-making, but also start to question their choices. They might recognize that something is essential in the long term, but are also incapable of weighing their immediate decisions.

This often leads to impulsive decisions such as skipping classes, avoiding homework, or staying out late with friends. While they recognize that their immediate decision isn't necessarily “good,” they lack the foresight to see how it could affect their life in the future. This is why teens are known for making mistakes; however, these mistakes are not necessarily bad.

Mistakes Are Educational, Especially During Teenhood

Some mistakes are commonly made during our teen years. Many teens have gotten into a fight with a friend, received detention at least once, or cut a class. While these things shouldn't be encouraged, they are learning experiences for a teenager. As their frontal lobes develop and these chemical changes occur, they're willing to take more risks. These risks, while uncalculated, are paving the way for them to explore their independence.

Not every decision will have negative consequences, either. Some decisions might look like befriending someone new, finally talking to their crush, or pursuing that impossible soccer goal. As a teen's brain develops, parents might notice their child becoming bolder, braver, and more impulsive in their choices. It then becomes the parents' job to ensure they're not taking too many risks, or any risks that could be harmful. Determining which mistakes to allow your teen to make vs. which to stop is one of the most challenging parts of parenthood.

How Do Hormones Affect a Teen as Their Brain Develops?

As all of the chemical changes happen in a teen's brain, hormonal shifts are also taking place. These further complicate the decision-making process. Oftentimes, this is where mood swings, irritability, and even isolation play a factor in a teen's behavior.

“Besides the fewer yet stronger connections, the child’s brain has other physical differences from a teen’s brain,” Dr. Schmidlkofer explains. “A teenager’s brain, with increasing hormones, will reduce the amount of hormone receptors in the brain. Both estrogen and testosterone receptors are down-regulated, likely due to such an increase in these hormones throughout the body.”

As this takes effect, Dr. Schmidlkofer also shares how this can lead to highly influential choices. “With increased autonomy in teenage years, there are more decisions to make for oneself. Some of these decisions can cause a lot of distress and anxiety due to the inability to see the potential benefits and consequences,” he says.

“This lack of foresight is a result of the still-developing brain trying to strengthen connections and learn. Therefore, mistakes are good for the brain to learn, but they can also cause uncontrolled emotions to be expressed. When emotions like anxiousness, fear, anger, and sadness are not controlled by a well-developed brain in a teenager experiencing more freedom, it can lead to behavioral issues with peers, parents, and teachers.”

When These Changes Manifest in Relationships

According to Dr. Schmidlkofer, the combination of these changes is entirely normal. However, they can manifest in ways that make a teen feel awkward or uncomfortable. “While adolescents are offered more autonomy and responsibility, an awkward teenage stage is a normal time in many lives,” he says. “The many physical changes lead to feelings of self-consciousness about one’s body and actions.”

This experience might be reflected in a teen's friend group or relationships. “This can lead to insecurity with peer groups and the other sex. This can be due to the immature and developing brain, but it is likely dependent on the necessity to please others to fit in with peers.”

How Parents Can Support Their Teens

During such an unpredictable transition, parents often wonder how they can support their children. Becoming a teenager isn't easy, and they'll face many challenges as they grow up. When sudden mood changes and impulsive decisions are factored in, many teens may look to the people around them for guidance.

“Personally, I think the biggest challenge that kids face is finding a supportive friend group where they can be themselves and discuss problems. This time of life is very dependent on their peers,” says Dr. Schmidlkofer.

“With many changes, including physical growth and appearance, school and classes, and students coming and going, a strong and stable friend group can help support these teenagers. When friend groups break up or separate due to adolescent problems, having a good relationship with your child can really help you empathize with them,” he adds.

As your teen figures out who they are, Dr. Schmidlkofer encourages parents to have a working relationship with their children. This will help them identify behaviors and patterns, which can then be discussed in a compassionate, open way. “While some adolescents may have obvious outbursts when they are struggling with emotions, many will be more subtle,” he says.

“Parents may observe apathy or sadness in their teenager, secluding themselves in the bedroom or avoiding conversations. Adolescents may stop hanging with usual friends or quit clubs or teams. These are all red flags to have a discussion with their child and properly work through these emotions.”

As your teen learns to navigate the world outside while their internal world shifts, the best thing a parent can do is be there for them.

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