Every generation has something to say about the one before. If you're talking about teenagers, well, there's plenty for fodder in the news. From extreme bullying to thoughtless antics such as flipping a signboard, and putting a drunk juice bottle back on a supermarket shelf during the COVID-19 pandemic, it's enough for you to exclaim: Just what were these kids thinking?
There was probably not much thinking involved because when it comes to the teenage brain, it isn’t quite fully developed yet – and it won’t be until age 25 or so. Because of that, good judgment isn’t something teens can excel in at the moment, according to Stanford Medicine.
While adults like yourself respond to situations using your prefrontal cortex (the brain’s CEO or rational part), the teenager tends to use his amygdala (the emotional part) instead.
And it’s not like there’s a 10 Year Series on making good judgement that teenagers can use to hone their thinking; that comes from life’s experiences, guidance and the skills they pick up along the way.
(Photo: iStock/Phynart Studio)
However, there are factors that can adversely affect the growing teen brain, some more insidious than others. For instance, the use of Kpods, alcohol and nicotine are known hazards; but did you know that junk food, skipping meals and the lack of sleep can impact adolescent brain development as well?
We find out how the teenage brain develops physiologically and what you can do to help it along if you have a teen at home.
Your brain matures in your mid-20s not by increasing in size. In fact, your brain has already finished growing by your sixth birthday.
“Rapid brain growth (that is, the increase in brain volume) occurs during the first three years of life and will reach adult size at about six years of age,” said Dr Yeo Tong Hong, a senior paediatrician and paediatric neurologist at Parkway East Hospital.
What does continue developing in teenhood and early adulthood is the refining of neural networks, which “takes longer than physical development because it depends on and is adapted to both biology and experience”, said Dr Chee Tji Tjian, a senior consultant with National University Hospital’s Department of Psychological Medicine. “This extended timeline allows for adaptability to our life experiences.”
In fact, “there is increasing evidence of changes continuing into adulthood”, according to Dr Tang Shan-Shan, a consultant with KK Women’s and Children’s Hospital’s (KKH) Neurology Service. “This slow, steady process allows the brain to change and build new connections as we gain experiences and learn new skills, including how we respond to physical and cognitive demands in our environment.”
(Photo: iStock/jambojam)
Brain maturation is about developing its connections, structure and function, said Dr Tang. And one of the ways it does this is by growing more brain cells (neurons) to create more complex pathways. This is a process known as neurocircuitry and it allows the brain to process information and control behaviour, she said.
In addition, there are two major developments that occur during brain maturation: Myelination and synaptic pruning. Myelination is the process in which fatty coatings are grown around the nerve fibres in the brain. Dr Yeo likened it to insulating electrical cables: “It prevents electrical current from leaking out and allows electrical currents to travel faster.”
Growing these coatings “improve processing speed and coordination across brain regions”, said Dr Chee. They also help to “sharpen thinking, improve memory, and support better emotional control as the brain matures”.
While all that is happening, the teenage brain is also busy doing some synaptic pruning. “It is the brain’s way of removing unused or weak connections between neurons, making neural pathways more efficient,” explained Dr Chee. And don’t worry; there are trillions of synaptic connections that formed rapidly between infancy and early childhood, which is more than the brain will ever need, he added.
A 3D illustration showing a synapse, the tiny gap between neurons. (Art: iStock/nopparit)
The more frequently used synaptic connections are strengthened to improve cognitive efficiency and adaptability. “This process, a use-it-or-lose-it mechanism, allows the brain to become faster and more focused,” said Dr Chee.
To put it simply, the brain matures in a general back-to-front sequence, said Dr Chee. It begins with areas responsible for basic survival functions before progressing to regions that support complex thinking and self-regulation, he said.
“One of the earliest systems to mature is the limbic system, which plays a key role in processing emotions and forming memories,” said Dr Chee. “Within this system, the amygdala is responsible for detecting and responding to emotional stimuli such as fear and pleasure.”
The hippocampus, which is part of the limbic system, gets upgraded as well. This is where short- and long-term memories form, and is the “library” of all your sensory information, including sight, sound and smell, said Dr Yeo.
Also included in the maturation list is the nucleus accumbens, said Dr Chee. It is the brain’s reward centre, and “drives motivation and the pursuit of pleasure”. “It is particularly active during adolescence,” he added.
The prefrontal cortex is the last region in the brain to cross the hurdle. “This is where many higher cognitive and executive functions, including decision making, planning, emotional regulation, attention and impulse control, personality and social behaviour, including stress management, reside,” said Dr Yeo.
(Photo: iStock/Real People Group)
You can already see how the brain’s maturation sequence explains your teen’s emotional outbursts and impractical decisions. “During adolescence, the emotional limbic system is already active, while the prefrontal cortex is still developing,” Dr Chee explained. “This mismatch contributes to the emotional reactivity, impulsivity and risk-taking behaviour commonly observed during the teenage years,” he said.
But “as the prefrontal cortex matures, individuals become better able to regulate their emotions, assess risks and respond with greater balance to life’s challenges”, said Dr Chee.
Yes, they do. Just as girls experience puberty earlier than boys, their brains also undergo the abovementioned reorganisation and synaptic pruning earlier than boys’ brains.
In a study published in Cerebral Cortex, Newcastle University researchers also found that girls tended to develop more connections across the two hemispheres of the brain, which allow the brain to work more efficiently – a phenomenon the experts credited to the brain reorganisation that occurs earlier in girls.
How the brain develops in adolescence may answer why females are more prone to depression than males, according to a study. In the brain scans of 147 girls and 157 boys in Europe, aged 13 to 15 years old, certain brain regions were found to develop differently in boys and girls at puberty.
"We know that mood upsets, particularly anxiety and depression, occur disproportionately in girls, and that women are twice likely as men to suffer from depression following the trend emerging during puberty," said the researchers. "We found that the puberty period is associated with significant brain changes in these mood-related brain areas."
However, the researchers cautioned against seeing this as a definitive link between the brain changes and mood changes, and further study is underway.
Collapse Expand
Since parts of the brain, such as the prefrontal cortex, are still maturing, certain substances can interfere with their development, “which can lead to difficulties with learning, thought processing and impulse control”, said Dr Juliet Tan Sher Kit, a consultant with KKH’s Adolescent Medicine Service. Which is why finding substances such as beer, cigarettes or Kpods in a teenager’s bag is every parent’s nightmare.
“The brain is more sensitive to the effects of substances during adolescence, which means that even small amounts can have a significant impact,” said Dr Tan. In etomidate abuse, for example, the sedative is known to lower the levels of a certain serotonin precursor (5-HTP; it helps to reduce sleep disorder) and neurotransmitter (gamma-aminobutyric acid or GABA; it promotes relaxation and sleep), leading to increased anxiety, sleep disturbances and panic disorders, she said.
Etomidate is used as an anaesthesia during surgery. (Photo: iStock/Jeniffer Fontan)
The overuse of etomidate can lead to adrenal toxicity and electrolyte disturbances, which can cause breathing difficulties, muscle weakness and cardiac arrhythmias, said Dr Tan. However, experts are still not quite certain about the long-term effects of etomidate as research is still emerging, said Dr Chee, but it “may have long-term neurotoxic effects”.
“Importantly, all these substances – nicotine, alcohol and etomidate – disrupt the dopamine system, which plays a key role in motivation and reward processing,” cautioned Dr Chee. “This disruption increases the risk of addiction and enduring behavioural issues as the developing adolescent brain becomes more sensitive to substances that overstimulate its reward pathways.”
“Childhood and adolescence are critical windows for brain development,” said Dr Yeo. During this period, abnormal brain development may result from nutritional deficiencies, genetics, environmental exposures and maternal health conditions. “The consequences can be lifelong and vary in severity,” he said.
(Photo: iStock/Rimma_Bondarenko)
As for what brain-friendly nutrients to load up on, said Dr Yeo, include docosahexaenoic acid or DHA (a type of omega-3 fatty) to support cognitive functions and emotional regulation in teens. “DHA also facilitates neurotransmission during neuronal migration and development”, along with anti-inflammatory and neuroprotective effects, he said.
It also helps to include B vitamins, such as B12, folate and thiamine, said Dr Tan. “They are important in the development of neural pathways, where a deficiency can affect one’s memory and language skills.
"Vitamins and magnesium
And if your teenager often skips meals, it might be a good idea to keep nagging him not to. “Skipping meals, especially breakfast, is linked to poorer behaviour, attention, cognition, memory, and academic performance in children and adolescents,” said Dr Chee.
“Long periods of missing meals can alter the structure and function of the prefrontal cortex and hippocampus, leading to reduced cognitive control, poor memory and heightened impulsivity,” he warned.
(Photo: iStock/pocketlight)
“Most people are unaware that children and teens need more sleep than adults,” said Dr Tan. To be more precise, six- to 12-year-olds require nine to 12 hours of sleep each night. Those between 13 and 18 years old should get eight to 10 hours of uninterrupted sleep a night.
“During sleep, the neural connections are strengthened, making it easier to store, retrieve and use information at a later stage,” said Dr Tan.
“Chronic sleep deprivation and irregular sleep pattern like weekend sleep-ins can affect one’s ability to concentrate, leading to increased irritability and emotional reactivity,” said Dr Tan. “The prefrontal cortex (part of the brain responsible for impulse control) is particularly affected by sleep deprivation. The adolescent brain needs consistent, adequate sleep for optimal growth and learning.
Continue reading...
There was probably not much thinking involved because when it comes to the teenage brain, it isn’t quite fully developed yet – and it won’t be until age 25 or so. Because of that, good judgment isn’t something teens can excel in at the moment, according to Stanford Medicine.
While adults like yourself respond to situations using your prefrontal cortex (the brain’s CEO or rational part), the teenager tends to use his amygdala (the emotional part) instead.
And it’s not like there’s a 10 Year Series on making good judgement that teenagers can use to hone their thinking; that comes from life’s experiences, guidance and the skills they pick up along the way.
(Photo: iStock/Phynart Studio)
However, there are factors that can adversely affect the growing teen brain, some more insidious than others. For instance, the use of Kpods, alcohol and nicotine are known hazards; but did you know that junk food, skipping meals and the lack of sleep can impact adolescent brain development as well?
We find out how the teenage brain develops physiologically and what you can do to help it along if you have a teen at home.
WHY DOES BRAIN MATURATION TAKE LONGER THAN PUBERTY?
Your brain matures in your mid-20s not by increasing in size. In fact, your brain has already finished growing by your sixth birthday.
“Rapid brain growth (that is, the increase in brain volume) occurs during the first three years of life and will reach adult size at about six years of age,” said Dr Yeo Tong Hong, a senior paediatrician and paediatric neurologist at Parkway East Hospital.
What does continue developing in teenhood and early adulthood is the refining of neural networks, which “takes longer than physical development because it depends on and is adapted to both biology and experience”, said Dr Chee Tji Tjian, a senior consultant with National University Hospital’s Department of Psychological Medicine. “This extended timeline allows for adaptability to our life experiences.”
In fact, “there is increasing evidence of changes continuing into adulthood”, according to Dr Tang Shan-Shan, a consultant with KK Women’s and Children’s Hospital’s (KKH) Neurology Service. “This slow, steady process allows the brain to change and build new connections as we gain experiences and learn new skills, including how we respond to physical and cognitive demands in our environment.”
(Photo: iStock/jambojam)
WHAT HAPPENS TO THE BRAIN AS IT MATURES?
Brain maturation is about developing its connections, structure and function, said Dr Tang. And one of the ways it does this is by growing more brain cells (neurons) to create more complex pathways. This is a process known as neurocircuitry and it allows the brain to process information and control behaviour, she said.
In addition, there are two major developments that occur during brain maturation: Myelination and synaptic pruning. Myelination is the process in which fatty coatings are grown around the nerve fibres in the brain. Dr Yeo likened it to insulating electrical cables: “It prevents electrical current from leaking out and allows electrical currents to travel faster.”
Growing these coatings “improve processing speed and coordination across brain regions”, said Dr Chee. They also help to “sharpen thinking, improve memory, and support better emotional control as the brain matures”.
While all that is happening, the teenage brain is also busy doing some synaptic pruning. “It is the brain’s way of removing unused or weak connections between neurons, making neural pathways more efficient,” explained Dr Chee. And don’t worry; there are trillions of synaptic connections that formed rapidly between infancy and early childhood, which is more than the brain will ever need, he added.
A 3D illustration showing a synapse, the tiny gap between neurons. (Art: iStock/nopparit)
The more frequently used synaptic connections are strengthened to improve cognitive efficiency and adaptability. “This process, a use-it-or-lose-it mechanism, allows the brain to become faster and more focused,” said Dr Chee.
DO CERTAIN PARTS OF THE BRAIN MATURE EARLIER THAN OTHERS?
To put it simply, the brain matures in a general back-to-front sequence, said Dr Chee. It begins with areas responsible for basic survival functions before progressing to regions that support complex thinking and self-regulation, he said.
“One of the earliest systems to mature is the limbic system, which plays a key role in processing emotions and forming memories,” said Dr Chee. “Within this system, the amygdala is responsible for detecting and responding to emotional stimuli such as fear and pleasure.”
The hippocampus, which is part of the limbic system, gets upgraded as well. This is where short- and long-term memories form, and is the “library” of all your sensory information, including sight, sound and smell, said Dr Yeo.
Also included in the maturation list is the nucleus accumbens, said Dr Chee. It is the brain’s reward centre, and “drives motivation and the pursuit of pleasure”. “It is particularly active during adolescence,” he added.
The prefrontal cortex is the last region in the brain to cross the hurdle. “This is where many higher cognitive and executive functions, including decision making, planning, emotional regulation, attention and impulse control, personality and social behaviour, including stress management, reside,” said Dr Yeo.
(Photo: iStock/Real People Group)
You can already see how the brain’s maturation sequence explains your teen’s emotional outbursts and impractical decisions. “During adolescence, the emotional limbic system is already active, while the prefrontal cortex is still developing,” Dr Chee explained. “This mismatch contributes to the emotional reactivity, impulsivity and risk-taking behaviour commonly observed during the teenage years,” he said.
But “as the prefrontal cortex matures, individuals become better able to regulate their emotions, assess risks and respond with greater balance to life’s challenges”, said Dr Chee.
DO TEENAGE GIRLS' BRAINS DEVELOP SOONER THAN TEENAGE BOYS'?
Yes, they do. Just as girls experience puberty earlier than boys, their brains also undergo the abovementioned reorganisation and synaptic pruning earlier than boys’ brains.
In a study published in Cerebral Cortex, Newcastle University researchers also found that girls tended to develop more connections across the two hemispheres of the brain, which allow the brain to work more efficiently – a phenomenon the experts credited to the brain reorganisation that occurs earlier in girls.
WHY FEMALES ARE MORE PRONE TO DEPRESSION THAN MALES
How the brain develops in adolescence may answer why females are more prone to depression than males, according to a study. In the brain scans of 147 girls and 157 boys in Europe, aged 13 to 15 years old, certain brain regions were found to develop differently in boys and girls at puberty.
"We know that mood upsets, particularly anxiety and depression, occur disproportionately in girls, and that women are twice likely as men to suffer from depression following the trend emerging during puberty," said the researchers. "We found that the puberty period is associated with significant brain changes in these mood-related brain areas."
However, the researchers cautioned against seeing this as a definitive link between the brain changes and mood changes, and further study is underway.
Collapse Expand
HOW DO SUBSTANCES SUCH AS ALCOHOL, NICOTINE AND ETOMIDATE AFFECT THE BRAIN’S MATURING PROCESS?
Since parts of the brain, such as the prefrontal cortex, are still maturing, certain substances can interfere with their development, “which can lead to difficulties with learning, thought processing and impulse control”, said Dr Juliet Tan Sher Kit, a consultant with KKH’s Adolescent Medicine Service. Which is why finding substances such as beer, cigarettes or Kpods in a teenager’s bag is every parent’s nightmare.
“The brain is more sensitive to the effects of substances during adolescence, which means that even small amounts can have a significant impact,” said Dr Tan. In etomidate abuse, for example, the sedative is known to lower the levels of a certain serotonin precursor (5-HTP; it helps to reduce sleep disorder) and neurotransmitter (gamma-aminobutyric acid or GABA; it promotes relaxation and sleep), leading to increased anxiety, sleep disturbances and panic disorders, she said.
Etomidate is used as an anaesthesia during surgery. (Photo: iStock/Jeniffer Fontan)
The overuse of etomidate can lead to adrenal toxicity and electrolyte disturbances, which can cause breathing difficulties, muscle weakness and cardiac arrhythmias, said Dr Tan. However, experts are still not quite certain about the long-term effects of etomidate as research is still emerging, said Dr Chee, but it “may have long-term neurotoxic effects”.
“Importantly, all these substances – nicotine, alcohol and etomidate – disrupt the dopamine system, which plays a key role in motivation and reward processing,” cautioned Dr Chee. “This disruption increases the risk of addiction and enduring behavioural issues as the developing adolescent brain becomes more sensitive to substances that overstimulate its reward pathways.”
WHAT ABOUT LIFESTYLE FACTORS SUCH AS NUTRITION?
“Childhood and adolescence are critical windows for brain development,” said Dr Yeo. During this period, abnormal brain development may result from nutritional deficiencies, genetics, environmental exposures and maternal health conditions. “The consequences can be lifelong and vary in severity,” he said.
(Photo: iStock/Rimma_Bondarenko)
As for what brain-friendly nutrients to load up on, said Dr Yeo, include docosahexaenoic acid or DHA (a type of omega-3 fatty) to support cognitive functions and emotional regulation in teens. “DHA also facilitates neurotransmission during neuronal migration and development”, along with anti-inflammatory and neuroprotective effects, he said.
It also helps to include B vitamins, such as B12, folate and thiamine, said Dr Tan. “They are important in the development of neural pathways, where a deficiency can affect one’s memory and language skills.
"Vitamins and magnesium
And if your teenager often skips meals, it might be a good idea to keep nagging him not to. “Skipping meals, especially breakfast, is linked to poorer behaviour, attention, cognition, memory, and academic performance in children and adolescents,” said Dr Chee.
“Long periods of missing meals can alter the structure and function of the prefrontal cortex and hippocampus, leading to reduced cognitive control, poor memory and heightened impulsivity,” he warned.
(Photo: iStock/pocketlight)
HOW DOES SLEEP AFFECT BRAIN DEVELOPMENT?
“Most people are unaware that children and teens need more sleep than adults,” said Dr Tan. To be more precise, six- to 12-year-olds require nine to 12 hours of sleep each night. Those between 13 and 18 years old should get eight to 10 hours of uninterrupted sleep a night.
“During sleep, the neural connections are strengthened, making it easier to store, retrieve and use information at a later stage,” said Dr Tan.
“Chronic sleep deprivation and irregular sleep pattern like weekend sleep-ins can affect one’s ability to concentrate, leading to increased irritability and emotional reactivity,” said Dr Tan. “The prefrontal cortex (part of the brain responsible for impulse control) is particularly affected by sleep deprivation. The adolescent brain needs consistent, adequate sleep for optimal growth and learning.
Continue reading...