When does brain growth stop? Here’s what science says
Clinically reviewed by Dr. Chris Mosunic, PhD, RD, MBA
Wondering when brain growth stops? Discover what changes in your brain through your 20s, when and why its stops, and 9 tips for supporting long-term brain health.
Experts often remind frustrated parents that children misbehave because their brains are still developing. Kids aren’t necessarily acting out on purpose — they literally can’t stop themselves.
But how long can that excuse work? As it turns out, brain growth is a long, layered process that continues through your 20s, and for some people, even longer. It evolves as you collect life experiences, heartbreaks, job stress, sleep debt, and the occasional existential crisis.
Still, there is a point at which your brain is better able to manage emotions and make decisions. Let’s break it down: when brain growth actually tapers off, what that means for your choices, and why your best thinking might still be ahead of you.
How do our brains develop?
The brain is constantly shaped by experience and is ultimately considered fully developed around age 25. In infancy and early childhood, development is rapid. Neurons form millions of connections per second, setting the stage for movement, language, attachment, and basic emotional responses.
By age 5, your brain reaches about 90% of its adult size, and it’s still refining itself. The brain is constantly optimizing, strengthening frequently used connections, and getting rid of the ones it doesn’t need. This ongoing process sets the stage for the next big chapter: adolescence.
Brain growth in adolescence
Adolescence is one of the most intense periods of brain reorganization. During this stage, the limbic system—the brain’s emotional and reward center—develops early. But the prefrontal cortex, which manages logic, long-term planning, and impulse control, lags behind.
This mismatch is part of how people build independence, identity, and emotional complexity. Additionally, during this period, the brain is slowly building adult-level thinking and emotional regulation. It also continues to mature and shape how you respond and reason through your mid-to-late 20s.
When does brain growth stop?
While most structural growth wraps up in your mid-to-late 20s, that doesn’t mean your brain’s frozen in time. While your foundational brain construction stops, refinement still continues to happen.
This ongoing adaptability is called neuroplasticity — the brain’s ability to rewire and reorganize itself in response to learning and experience. Also, factors like sleep, stress, trauma, nutrition, exercise, and social connection continue to influence how your brain functions day to day for the rest of your life.
5 ways brain development impacts your choices
Your brain shapes how you see the world and how you make decisions. As it matures, especially through your teens and 20s, that growth directly affects your choices. Here’s how:
1. Emotions settle with age: Teens and young adults typically feel emotions intensely because their emotional centers mature before their logic centers do. As the prefrontal cortex develops, emotional reactions become easier to manage.
2. Planning gets easier in your 20s: The ability to think ahead, set goals, and weigh consequences usually improves with age, often as you reach your mid-20s.
3. Risk-taking slows down: Younger brains are wired to seek novelty. But that energy usually levels out with age as your reward system balances, and your thrill-seeking gets more grounded.
4. Empathy deepens: Skills like reading emotions and navigating social situations tend to improve over time. This is because your brain is slowly wiring itself to better understand others.
5. Lifestyle still matters: Even after major development ends, your brain is still responsive to what you feed it. Good sleep, low stress, quality nutrition, and connection keep it strong and adaptable for life.
How to strengthen your brain at any age: 9 science-backed tips
For the most part, everyone’s brain continues to change throughout their life. But you do still have to work with it to make that a reality.
Here are 10 research-backed ways to support your brain, no matter your age, attention span, or current bandwidth.
1. Prioritize quality sleep
During deep sleep, your brain usually processes emotions and clears out waste products. But if you consistently don’t get enough of it, it can reduce your cognitive function and slow your reaction times.
To operate at your fullest potential, aim for 7–9 hours most nights.
2. Move your body
Exercise can increase blood flow to the brain and boost the production of BDNF — brain-derived neurotrophic factor. This is a protein that helps neuroplasticity and memory.
To help your memory, move your body regularly. You could do a brisk walk, 10 minutes of stretching, or even dance around your bedroom.
Here are seven other simple movement exercises that can boost your mental health.
3. Feed your brain with nourishing foods
Diets rich in whole foods—like leafy greens, berries, fatty fish, and nuts—are associated with better cognitive function and reduced inflammation.
To help you think more clearly, add spinach to your smoothie and keep a small bag of walnuts at your desk.
💙 Nourish your brain and body by listening to Tamara Levitt’s Mindful Eating Series.
4. Protect your brain from chronic stress
Chronic stress can shrink areas of the brain related to memory and increase inflammation. Counterbalance this by creating micro-moments of calm.
What does this look like? Breathe slowly for 60 seconds between meetings, ground yourself by feeling your feet on the floor, or practice naming your emotions to give your brain a break from bottling them up.
5. Stay socially connected
Our brains tend to function more effectively when we feel supported and acknowledged. To avoid cognitive decline, make a concerted effort to text someone just to say hi.
You could also join a book club or schedule regular phone dates with your best friend.
Read more: How to make & keep friends as an adult: 10 ways to connect
6. Challenge your brain regularly
Solving problems, learning new skills, and exposing yourself to unfamiliar ideas can help maintain your cognitive flexibility.
Challenge your brain by learning a few phrases in a new language or by playing a logic puzzle one or two days a week.
7. Practice mindfulness or meditation
Mindfulness can change your brain. It may improve focus, reduce reactivity, and strengthen regions related to empathy and emotional regulation.
To help your awareness, try breathing in for four counts and out for six. This can take you out of your head and into the present.
💙 Bring yourself into the now by listening to this Mindfulness meditation with Tamara Levitt.
8. Limit substances that disrupt brain function
Excessive alcohol, drugs, and high-sugar diets can impair memory, mood, and focus. Be mindful of how they impact you. Awareness can help you make choices that support your brain — and not sabotage it.
9. Keep your mental environment stimulating
Doomscrolling and constant multitasking can overload your brain and reduce your attention span. After all, your brain needs space to integrate, rest, and recharge.
Give your mind some quiet time by turning off notifications an hour before bed or by listening to a podcast instead of endlessly scrolling on your phone.
When does brain growth stop FAQs
When do our brains fully develop?
The human brain is typically considered fully developed by around age 25. That’s when the prefrontal cortex—the part responsible for emotional regulation and impulse control—finishes maturing.
But this doesn’t mean that your brain’s static. The brain still remains plastic and can continue learning, adapting, and forming new neural pathways for the rest of your life.
What part of the brain develops last?
The prefrontal cortex is the last part of the brain to develop. This area is responsible for executive functions, including decision-making, risk assessment, and self-control.
It matures later than areas like the limbic system, which drives emotion and reward. This is why teens tend to have big feelings and limited impulse control.
Why is teen brain growth so important?
Teen brain growth sets the foundation for adulthood. During this time, the brain determines which connections to retain and which to discard based on past experiences.
This makes adolescence a time of enormous possibility, but also vulnerability. Habits, stress, and sleep patterns can all have a significant impact during this window as well.
Can brain growth continue past your 20s?
Brain growth does continue past your 20s. While major structural development slows down in your 20s, your brain still remains plastic. It continues to form new connections and adapt to change.
Also, adults continue to learn new skills, shift mindsets, and even rewire emotional patterns. Practices like meditation, learning, physical activity, and therapy can all encourage ongoing neural growth.
What affects brain growth in teens and young adults?
Several factors can shape their brain development. Quality sleep can support memory and emotional regulation. On the flip side, chronic stress and trauma can disrupt their development.
To ensure your brain grows stronger and more resilient, surround yourself with environments that provide emotional safety, cognitive stimulation, physical activity, and social connection.
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