Things were changing in our household: the teen years had intruded into our otherwise harmonious, do-as-mom-tells-you relatively
orderly world. As my two sons, who are two years apart, gradually began the "morphing" process from childhood into adolescence, I felt many things shift, most obviously our parent-child relationship. We were not unusual: this was happening in the families of all of their classmates and friends. As a novice parent of a teenager, I would marvel at the disconnects: the ability to be so focused on a sport or a math test victory concurrently with major lapses in judgment or planning, misguided acts and pranks with no consideration of the consequences. Most of all, my kids were not predictable anymore, neither to me nor even to themselves.
I consciously made the decision to remain curious rather than angry by all the unexpected things that happened on a near daily basis. As a physician used to seeing teen patients, it was disarming to be experiencing this transition into adolescence up close and personal in my own family. It didn't take long for me to delve into the scientific literature on brain development in teens, which is a more recently evolving area of study, compared to decades of brain research on early childhood and the aging brain. I discovered many fascinating facts that were both good news about the strengths of the teen brain and bad news about its high vulnerability to things like stress, drugs, and alcohol. I found myself sharing these explanations with teachers at school, with other parents on the sidelines of sports events, and at dinner parties where the topic would often hijack the conversation.
The brain is the last organ in the body to fully mature, and estimates now are that the process is likely not complete until the late 20s or early 30s. Remarkable new magnetic resonance imaging (MRI) techniques have been applied to brain research and show that the full connectivity does not happen until at least the mid-20s. Indeed, the "front" of the brain includes the frontal and prefrontal cortex, and these are regions that are the seat of insight, judgment, reasoning, impulse control, and empathy. This readily explains the impulsivity of the teenager and lack of ability to "connect the dots" when it comes to consequences of their actions. In a nutshell, the brain during the teen and young adult years is in major building mode, and the teen brain is novelty-seeking and impressionable. Neurons, the brain cells responsible for memory and learning, communicate with each other through synapses, and these synapses are highly excitable and "plastic" during childhood and the teen years. Synapses actually sort of grow when they are used a lot; hence practice results in a bigger, faster, and more powerful synapse, which can aid in mastering memorization, musical skills, or athletic performance. This biological programming makes it easier to learn, remember, and develop skills in adolescence compared to adulthood.
Unfortunately, this plasticity is also the underpinning for addiction. Research has shown that, like during learning, synapses get overactivated by substances, and then reward-seeking circuits get overstrengthened and cause an addicted state. A very concerning body of literature has emerged: adolescent brains, due to their more plastic synapses, can become addicted faster, harder, stronger, and more permanently than the adult. For instance, we all know those people who became addicted to cigarettes during their teen years and have a much harder time trying to quit than people who picked up smoking as adults. In The Teenage Brain, I review how each of the most common negative "stimuli" teens encounter have been shown to modify brain development at this critical stage: drugs like cocaine, marijuana, ecstasy, and nicotine, as well as environmental factors like stress, digital overload, and sleep deprivation. The effects range from altered IQ to addictability and mental health issues.
Although nature designed adolescence to be a prep time for adulthood — a time to test limits and learn how to cope with what awaits them in adulthood — teens today face a major challenge in this digital age. In our ever-connected society, what was intended as a lighthearted prank or a passing embarrassing moment can be immortalized in nanoseconds and can go viral globally, resulting in profound consequences for the victim(s). In addition to the challenges of navigating social media while building their identities and understanding long-term consequences of their actions, teens can also be exposed online to excessively stressful material that they may be unprepared to comprehend, as well as access to easy conduits for substances to abuse.
Despite the challenges facing teens today, there is a major upside to this impressionable stage in the lives of young adults. When presenting this material at middle schools and high schools, I have found the teens themselves to be intrigued with the science of their differences, and to actually be extremely thoughtful about all this new research. After all, this is the first teen generation that has had this level of information about their developmental stage available to them. As teens become more aware of their special status during this part of their lives, they can focus on honing their strengths and softening their weaknesses in academics or motor skills. This is truly a time of privilege along those lines, and the decisions teens make during these critical years may have a lasting impact, not only on their lives, but on their brain as they enter adulthood.