What It Means
The teen brain is the brain during adolescence, when it has reached its full size but is still being fine-tuned. According to the National Institute of Mental Health (NIMH), the brain doesn't finish maturing until the mid-to-late 20s, and that the prefrontal cortex, the area behind the forehead used for planning, setting priorities and making decisions, is among the last parts to get there. Changes in the parts of the brain that handle social life also pull teens toward their friends.
Try It: Flip Through NIMH's Seven Teen Brain Facts
Tap each card to open it. All seven come from NIMH's "The Teen Brain: 7 Things to Know."
1. Still developing
Full size by early adolescence, but not fully mature until the mid-to-late 20s. The planning area behind the forehead matures last.
2. Friends matter more
Social changes turn teens toward peers, which can lead to risks. Some are dangerous; some are good, like joining a new club.
3. Ready to learn
Hard classes, exercise, art and music can strengthen brain circuits.
4. Stress hits differently
Teens may react to stress differently than adults, which can raise the chance of anxiety and depression. Coping skills help.
5. Sleep shifts later
The sleep hormone melatonin stays elevated deeper into the night and lingers into the morning, and many teens are short on sleep.
6. Mental illness can start
Many conditions, including anxiety, depression and eating disorders, first show up in the teen years.
7. Built to bounce back
Most teens grow into healthy adults, and some brain changes support long-term resilience.
Worried about your teen's safety? Call or text 988. In a life-threatening situation, call 911.
How Parents Say It
- "He's smart, he just doesn't think things through yet."
- "She can't fall asleep before midnight and can't get up for school."
- "It's all about her friends right now."
The Breakdown
How the brain changes by stage, per NIMH
| Stage | What's happening |
|---|---|
| Early adolescence | The brain stops growing in size |
| Teen years | Fine-tuning of how the brain works; friends and social life take center stage |
| Teen years | Melatonin stays elevated deeper into the night and lingers into the morning, so sleep shifts later |
| Teen years | Many mental illnesses first appear, including anxiety, depression, bipolar disorder, schizophrenia and eating disorders |
| Mid-to-late 20s | The brain finishes maturing, with the prefrontal cortex among the last areas |
What this means at home. NIMH says challenging classes, exercise and creative pursuits such as art or music can build up the brain's circuits, so those activities are worth backing. Peer-driven risks aren't all bad: NIMH's own examples of positive risks include striking up a conversation with a classmate they don't know yet, or signing up for a new club or sport. Many teens don't get enough sleep, which NIMH links to trouble paying attention, controlling impulses and doing well at school.
When to get help. NIMH suggests talking openly with your teen's doctor about any concern for their mental health. Changes in mood, sleep or behavior that worry you are worth raising.
Good to Know
If your teen is struggling or thinking about suicide, you can call or text 988 to reach the 988 Suicide and Crisis Lifeline, or chat at 988lifeline.org; that's the help NIMH lists. In a life-threatening situation, call 911. NIMH also notes that most teens grow up to be healthy adults, and that some brain changes in these years support resilienceResilienceThe capacity to adapt and keep developing well in the face of hardship. In children it's built above all through a stable, supportive relationship with an adult. See more over the long run.
FAQ
At what age is the brain fully developed?
NIMH puts the end of brain maturing in the mid-to-late 20s, and says the prefrontal cortex, used for planning and decisions, matures among the last.
Why do teenagers take more risks?
NIMH explains that a growing focus on friends, while the prefrontal cortex is still maturing, may lead teens to take more risks when the social payoff seems worth it. Some of those risks are positive, such as joining a new club.
Why do teens stay up so late?
NIMH says that in teens the sleep hormone melatonin stays elevated deeper into the night and lingers into the morning, which may explain late nights and hard mornings.
Do It in Buhata
Calendar
Put a regular one-on-one time with your teen on the Calendar in your Household Space in Buhata, so it happens even in busy weeks.
Open BuhataRelated Terms and Categories
- Puberty
The years when a child's body matures into an adult's, usually starting between about 8 and 13 in girls and 9 and 14 in boys, per Cleveland Clinic.
- Tween
A child in the years just before becoming a teenager, roughly the late elementary and middle school years. Another word for preteen.
- Executive function
The mental skills that let a person plan, focus, remember instructions and control impulses: working memory, mental flexibility and self-control.
Sources
National Institute of Mental Health, "The Teen Brain: 7 Things to Know" (NIH Publication No. 23-MH-8078, revised 2023); 988 Suicide and Crisis Lifeline
Last updated .