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‘What Were You Thinking?’

Rethinking the teen brain...

Stanley Kutcher, MD, FRCPC

Reprinted from "Young People" issue of Visions Journal, 2013, 9 (2), pp. 8-9, 31

What parent of a teenager has not asked their offspring that question? And not received an irrational or defensive answer?

So what is it about adolescence that raises so much adult incomprehension? What is it that prompted Shakespeare, in The Winter’s Tale, to write:

“I would there were no age between ten and three-and-twenty, or that youth would sleep out the rest; for there is nothing in the between but getting wenches with child, wronging the ancestry, stealing, fighting.”

What is it about adolescence that sometimes leads adults to the question: “Do you really have a brain, or are you just not using it?”

The answer is “yes” to the first question, and “it depends on what you mean” to the second one. Not only does the adolescent have a brain, but she or he is likely using it—as it was designed to be used. The challenge is both in the use and in the design!

Indeed, thank goodness for the adolescent brain. This rapidly developing brain that makes the years from 12 to 25 such an ‘exciting’ time—for everyone! It doesn’t take a long look back through history to realize that most of the great discoveries, explorations and huge leaps in civilization were the result of the teenage brain. It wasn’t middle-aged men and women that discovered the Americas. Steve Jobs and Bill Gates weren’t in their 40s when they revolutionized technology. And Einstein was barely post-acne when he came up with the theory of relativity.  

The teen years are characterized by the third phase of rapid and extensive brain development and remodelling (prenatal and early childhood being the first two phases). During this time, the brain develops substantially and quickly, and the so-called “teen behaviour” is a reflection of that biological fact.

One of the first domains to undergo rapid expansion is the easily aroused incentive processing systems of the middle brain. These systems generally depend on dopamine (a brain chemical that transmits messages from one brain cell to another) signalling for their activation, and they drive behaviour that feels good. They also enhance the attention given to rewards, preferring immediate rather than delayed reward. These systems are linked to complementary systems that drive sensation and novelty seeking, which results in easier and greater emotionality when switched to their “on” position. This switch goes on as a result of genetically programmed brain development at the time of life we call adolescence.

This collection of brain systems matures early in the teen years and coincides with sexual maturity (the biological ability to procreate). So it’s not the increases or changes in “hormones” that drive teen behaviours, but the changes in the brain systems that create and push out the hormones. Our common belief that adolescent behaviour is due to their hormones confuses correlation with cause.

While the teenage incentive processing systems are involved in evaluating and predicting potential rewards and punishments, they are also involved in processing social and emotional information. This helps explain why teens respond with enhanced and more rapid emotional changes to social stimuli that is both negative (such as gossip) and positive (such as praise).

And—you guessed it—these emotional responses are much more robust and less constrained in the presence of their peers. That is, during the teen years, peers actually have a greater influence on teen behaviour than peers do earlier or later in life. Why, we don’t know, but speculation includes the idea that it may have to do with learning how to “fit in” socially.

These reward and stimuli systems encourage innovation and exploration. They are the neural basis of why young people are not content to accept the status quo, but rather seek out new situations and see old problems in a new light.

The cognitive control system, located in a part of the brain called the dorsolateral prefrontal cortex, is slower to mature, however. This system is responsible for working memory, logical reasoning, planning, impulse regulation and so on—basically, it is where ‘civilization lives.’ So, this part of the brain can be considered to be, in part, a complex brake, working to help mould and modulate the activity of the reward and stimuli systems.

Along with the maturation of this biological “brake” (the cognitive control system), there is rapid enhancement of the connection between the incentive processing and cognitive control systems. So, as young people grow older and ‘civilization’ develops, so does the superhighway that allows ‘civilization’ to rein in the runaway novelty- and sensation-seeking parts and the incentives-processing parts.

So there we have it. The well-known risk-taking behaviours of adolescents are not simply about them “finding their identity” or “acting out of spite,” and they’re not a “sign of immaturity.” No, these behaviours are the result of genetically programmed brain development that has benefited the continuation and success of our species for countless generations. Remember Einstein, Gates and countless others!

But what about the negative fallout? The higher rates of accidents, social failures (e.g., criminal misadventure, and academic and vocational problems), early death, substance misuse and the like? Do we just have to accept this carnage and write it off to “that’s biology”?

Not at all.

We know that the brain develops not only in response to its genetic blueprint, but also in relationship to its environment. That amazingly complicated interaction between genes and environment is what drives the brain to adapt to its circumstance. It’s the reason we are here today.

Thus, it doesn’t take a rocket scientist or a brain surgeon or even a psychiatrist to figure out that the type of environment a teen is in will have a huge impact on how those risks are taken and how those incentives are experienced and achieved.

We can work to create environments that allow for enriched and challenging exploration that results in positive social and personal outcomes for young people. Or, we can allow teens to muddle along in environments that increase the likelihood that outcomes will be less than optimal. For them and for the rest of society.

This realization has profound implications for parenting and for social policy. It means that active, involved and caring parenting doesn’t end in childhood. It means our communities must invest in creating optimizing environments for youth and with youth. We need to rethink what roles our schools should be playing. And we need to start providing all teens with the opportunity to effectively direct their risk-taking and exploration, so they are more likely to experience positive rather than negative outcomes.

Hey, they do have a brain after all, and a good one! So it’s time for us to start seeing more of the positives that this exciting period of life can bring to young people, their families and their communities. It’s time for us to embrace the adolescent years, enjoy them and help provide the kind of challenges to our youth that, in hindsight, we wish we had experienced.

 
About the author
Stan is a leading authority on child and adolescent psychiatry. He holds the Sun Life Financial Chair in Adolescent Mental Health at Dalhousie University and the IWK Health Centre in Nova Scotia

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