Teenaged Brain: Part 1

This statistic is as familiar as it is startling. According to the National Comorbidity Survey-Replication (NCS-R), the peak age of onset for any disease involving mental health is 14 years. True for bipolar disorder. True for anxiety. True for schizophrenia and substance abuse and eating disorders. The data suggest that most mental health challenges emerge during adolescence. If true, this brings to mind an important developmental question:

What is up with adolescence?

The teenaged years are chock-full of byzantine, intricately timed, molecular processes that have to be closely choreographed and deployed in a specific sequence to accomplish their sexual mission. Do these extraordinarily complex developmental processes go awry in some children as they evolve through adolescence? Do these changes create, or at least contribute, to future mental disorders? Is this one way to get at what are sometimes called genetic “trapdoors”—DNA-based psychopathologies that do not show up until a certain developmental milestone is reached?

These are important issues. Most of the mental health challenges that emerge during puberty have real staying power. The symptoms tend to be more severe. Many go undetected in the early formative stages of the illness and comorbid disorders often develop. These complications can create problems in determining the correct diagnosis, and make it difficult for the clinician to select the treatment strategies with the greatest probability of success.

Researchers face similar daunting challenges in attempting to understand the cellular and molecular basis for such disorders. Fortunately, fairly recent findings have provided a ray of hope—potential illumination for both clinician and scientist. From gene to cell, we are beginning to learn more and more about the neurobiological maturation of the brain transiting through adolescence. The question is, Does any of this knowledge help us understand the NCS-R data?

In this column and the next, we will explore the developmental biology of the so-called teenaged brain, focusing first on cellular studies, then on behavioral ones. In this first installment, we will address specific aspects of the brain’s developmental trajectory. We’ll look initially at structural changes and then focus on the notion of the canonical “teenage brain” behaviors.

In the second installment, we will discuss how changes in these developmental processes may contribute to the emergence of mental disorders.

Read the column