As a physician, it’s likely you’ve counseled a parent or two who are confused or frustrated with their teenagers. And if you have parented a teenager you may have personal experience with those exact feelings.
The confusion is compounded by the fact that brain research on this developmental stage has not kept up with that of early and late life. This was the point made by Frances E. Jensen, MD, at the American Academy of Neurology meeting in May. Jensen is the author of The Teenage Brain, and Chair of the Department of Neurology, Perelman School of Medicine at University of Pennsylvania. She emphasized that this lack of research has led to many myths about teenagers—myths such as “teens are lazy” or “adolescents are impulsive and unreliable.”
But Dr. Jensen pointed out some actual facts about the teen brain during her presentation.
For example, melatonin is released later in teenagers than in children and adults. So that teenager who appears lazy is actually being forced to adapt their activities to an adult’s circadian rhythm. Consequently, teens like to sleep late, and their grades suffer in early morning classes compared to their counterparts who take the same class in the afternoon.
Another fact is that adolescent synaptic plasticity is superior to that of adults. This has a significant impact on learning. Plasticity is needed for learning, and repeated activation of a synapse mimics the “practice effect” and causes a larger synapse. This allows the teen to learn more quickly than adults. In fact, IQ can change during adolescence, which is why academic tracking is problematic. A student who reads more will likely have a higher IQ by age 17.
While heightened plasticity is critical to learning, it comes with potential problems. Addiction, for example, is a form of plasticity. Just as teens learn faster than adults, they can get addicted faster than adults. There is a legitimate reason the use of illicit substances is particularly concerning in teens.
Nicotine for example, is particularly problematic with the advent of electronic cigarettes. JUUL, a popular e-cigarette brand, has as much nicotine as a PACK of cigarettes. Electronic cigarettes have been associated with subsequent use of tobacco cigarettes in U.S. teens.
Another big concern for adolescents is alcohol use. It blocks plasticity and alters synapses permanently. Binge-drinking can also cause hippocampal cell loss which compromises impulse control.
And marijuana, which is lately gaining popular favor as a “less harmful” substance than alcohol or cigarettes, is problematic when it comes to teen brain development. It blocks long-term synaptic plasticity in the adolescent brain, and chronic cannabis use in teens can have a negative impact on IQ later in life.
For physicians, particularly neurologists, being able to explain the brain differences in teens can make them a valuable counselor to parents, schools, and communities. They can recommend appropriate adjustments to maximize learning and minimize the negative effects of enhanced plasticity such as addiction. It may not end the concern or frustration parents have with their teenagers, but it can offer peace of mind during some of the unavoidable trials of parenthood.