How your brain changes in adolescence

The brain is the most critical organ in the body (according to the brain)

From the moment we are born, our brains are buzzing with development and growth. Until our mid-twenties, our brains are undergoing constant changes. The crucial structures and pathways are present by the time most of us are 9-years old. Our teenage years can be some of the most drastic in terms of cognitive development. Researchers used to think that brain development had finished mainly by the time a child had finished growing. In reality, the brain goes on adapting and growing until a person is 25-30 years old. The last part of the brain to fully mature is the prefrontal lobe. (i)

Using magnetic resonance imaging (MRI), researchers have shed light on some of the ways our brains change and grow during our adolescent years. The brain does not change much in size between the ages of 5 and 20. What changes significantly are the connections between the different areas and regions in the brain. (i)(ii)

The brain is believed to develop and connect regions in stages. The limbic system is associated with emotions and is present from the moment we are born. Regulation of emotions tends to be shared between parent and child in the early years of life. Still, it becomes an individual responsibility as we grow into teenagers. This shift requires our brains to forge new connections between the areas responsible for higher-level thinking and the places associated with emotions. The new links will improve decision making, thinking and future-planning.

A massive re-wiring

Research has found that we often think with our emotions during our teenage years. Brain scans have shown those different areas of the brain light up when being used. When faces showing other emotions are presented to adults and teenagers, the brain activity is different. Teenagers make greater use of their amygdala to identify the emotions on strangers’ faces. Adults use their prefrontal cortex to recognise emotions in expressions. This shows that adolescents tend to use emotions to try and understand emotions in other people. (ii)

The best way to understand this is to imagine a stressful situation we have all been in. Late for school and struggling to find your phone, you keep checking where you usually leave it in the morning. As you realise that you have no time, you start to panic. Feeling alarmed is the result of relying on your emotions, not your prefrontal cortex. To understand how teenagers feel, remember how you last reacted when somebody told you to calm down and check the place you just looked in. Teens have not yet developed the link in their brain architecture, so they run on emotions. (ii)

Because of the massive reshuffle the brain goes through in your teenage years, it can often be easy to misinterpret emotions in other people. Sometimes it can be easy to perceive anger in somebody who is feeling anxiety, which can lead to miscommunications. An easy way to resolve this is to check that you’re on the same page as the other person, regarding how you both feel.

Supporting Your Think-Box

As your brain grows, it will develop countless new connections that can develop and strengthen. The brain develops in a way that makes lots of connections which are lost if they are not used. Alcohol and drugs can be poisonous to the developing brain. During adolescence, the existing connections between brain cells are reinforced and will set for life. Alcohol and drugs at this stage can affect memory and organization. (iii) Therefore, optimal brain development is dependent on practicing healthy habits early. If you look after your brain now, it will surely look after you in your adult years.


i. Konrad, K., Firk, C. and Uhlhaas, P.J. (2013). Brain Development During Adolescence. Deutsches Aerzteblatt Online. [online] Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3705203/ [Accessed 29 Jan. 2021].

ii. Sharma, S., Arain, Mathur, Rais, Nel, Sandhu, Haque and Johal (2013). Maturation of the adolescent brain. Neuropsychiatric Disease and Treatment, [online] p.449. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3621648/ [Accessed 29 Jan. 2021].

iii. Ministry of Health NZ. (2019). Alcohol. [online] Available at: https://www.health.govt.nz/your-health/healthy-living/addictions/alcohol-and-drug-abuse/alcohol [Accessed 29 Jan. 2021].


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