Adolescence is a heady time of emotional highs and lows, incredible passion and energy, but it can also be risky and dangerous. So it's no wonder that many parents approach this period with fear and trepidation.
Nature has created this change in the reward circuitry so it becomes much more rewarding to take risks, with the lower dopamine to feel restless and bored with the familiar home environment, and to push for something new.
After reviewing the past 20 years of research into brain development, Siegel and his colleagues found things that really bust some of the myths around teenage-hood. One such myth is that adolescence is a time of life dominated by raging hormones. ‘This is not the story,’ Siegel says, and claims that the hormones theory disempowers young people, because it seems there’s not much they can do about it.
He suggests that if parents and teens can work together to form a deeper understanding of the brain science behind this stage, they could turn conflict into connection, giving young people a happier and more stable entry to adulthood. Interestingly, he defines adolescence as extending well beyond the teens, from the ages of 12 to 24.
During this time the brain is re-modelling, and the first part of this process is known as pruning. At about 12 or 13 years of age, the brain naturally starts to prune away an abundance of synaptic connections between its cells, destroying some neurons that have been laid down during childhood.
The next stage of re-modelling is when myelin is laid down. ‘Myelin allows the existing neurons, the ones that have remained through a use-it-or-lose-it principle [to be] 3,000 times more effective at communicating with each other,’ he says. ‘An integrated brain is actually more specialised and more efficient.’
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The question is why these changes take place. According to Siegel, the brain has to change fundamentally in order to prepare children for adult life.
‘Imagine that you are at home and you're in bed, you're a young child and it's early morning, and as the sun rays come in, your mum comes in who loves you like crazy, she kisses you gently on the forehead and she says, “Good morning, what would you like for breakfast?” And you say, “Oh Mum, I think I'll have some oatmeal”.’
‘You come downstairs after you get dressed in your clothes for school and you have this delicious oatmeal and you go off to preschool, you learn to play with your friends and share toys, you take a little rest and you have a snack, you play some more and then you come home, you play outside, you get a little dinner before you go take a bath, someone scrubs you down, they then put you in your pyjamas, you then get in bed and they give you a massage, sing you a song, read you a story and you fall off to sleep. Why would you leave?’
Something fundamental has to change in the child to prepare the adolescent to leave the safety and security of home. ‘You have to change the brain in a way that's going to get it drawn to the unfamiliar, willing to engage with the unsafe, and to thrive with the uncomfortable,’ says Siegel.
So in addition to re-modelling, changes occur in the reward circuitry of the brain, which communicates within itself using a chemical called dopamine. During adolescence, the baseline level of dopamine is lower. Dopamine is released when people engage with novelty, the unfamiliar and the uncertain.
‘Nature has created this change in the reward circuitry so it becomes much more rewarding to take risks, with the lower dopamine to feel restless and bored with the familiar home environment, and to push for something new,’ says Siegel.
The upside of this is that teenagers get ready to leave home, but the downside is they do risky things. At the same time, the evaluative circuitry of the brain is skewed, favouring the exciting and adventurous aspects of a choice. This is called hyper-rational thinking and when it is combined with the dopamine reward system changes, it helps us to understand teenage risk-taking behaviour.
Adolescents know about the dangers involved in fast driving for example, but often choose to do it anyway.
‘Sadly, even though the body of an adolescent is much stronger than any other time, during the second dozen years of life, you are three times more likely to be seriously injured or die from preventable causes,’ says Siegel.
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Adolescence is also the time when we are at greatest risk of becoming addicted to illicit drugs, tobacco, or gambling and of developing mental illnesses like schizophrenia, depression and anxiety disorders.
‘What we believe is happening is that the pruning process during the adolescent period is unmasking vulnerable circuits, but before the pruning, that is during childhood, it was fine. That's why adolescence is the time when we are most likely to develop the onset of one of these disorders that can last a lifetime.’
Siegel says that these disorders are due to some impairment in the fundamental drive of the adolescent brain to become integrated. An integrated brain, he says, is a function of wellbeing. Siegel himself has two children, now in their twenties.
‘They had very typical adolescent periods,’ he says. ‘I think the biggest challenge for us, and maybe for any parent of an adolescent, is you don't treat an adolescent like a child, this is really disempowering and humiliating. They are at a very different stage of life.’
‘I've got to say, I am extremely proud of who each of them have become, who they are, and also I am learning from them. They each have taught me tremendously about how to get my essence back, and I'm very grateful for them.’
An exploration of all things mental, All in the Mind is about the brain and behaviour, and the fascinating connections between them.