Brain in Progress: Why Teens Can’t Always Resist Temptation

It’s National Drug Facts Week, when middle and high schools all over the country host events to raise awareness about drugs and addiction, with the help of scientists from the National Institute on Drug Abuse (NIDA). The issues I discussed in my TEDMED talk "Why Do Our Brains Get Addicted" —the changes in the brain common to obesity and drug addiction—are especially pertinent to the struggles teens face to resist drugs, because adolescence is a crucial period both of susceptibility to the rewards of drugs and of vulnerability to the long-term effects of drug exposure.

Adolescence is a time of major brain development—particularly the maturation of prefrontal cortical regions involved in self-control and the neural circuits linking these areas to the reward regions. The prefrontal cortex, where we make decisions and comparative judgments about the value of different courses of action, is crucial for regulating our behavior in the face of potential rewards like drugs and food. Adolescents are prone to risky behaviors and impulsive actions that provide instant gratification instead of eventual rewards.  In part, this is because their prefrontal cortex is still a work in progress.

The incomplete maturation of the prefrontal cortex is a major factor in why young people are so susceptible to abusing drugs, including alcohol, tobacco, marijuana, and prescription drugs. There are numerous pressures in their lives to try these substances (stress and peers, for example), but inadequate cognitive resources to help them resist. Because their brain architecture is still not fully developed, adolescents’ brains are more susceptible to being radically changed by drug use—often specifically by impeding the development of the very circuits that enable adults to say “later” … or “not at all” … to dangerous or unhealthy options. Thus, when drug abuse begins at a young age, it can become a particularly vicious cycle. Research shows that the earlier a teen first uses drugs, the likelier he or she is to become addicted to them or to become addicted to another substance later in life. It is likely that the same dynamics are at play when it comes to fattening food and the brain’s reaction to it.

Though parents may get frustrated by their teens’ poor decisions at times, they usually forgive them—because on some level adults understand that kids’ internal guidance systems aren’t yet fully functional. People often have a harder time extending that same forgiveness to adults who suffer from addictions or obesity, because we think they should be better able to control their impulses.  But, the fact is that their internal guidance systems, too, are compromised. For such individuals, it is not a question of free choice or just saying no to temptation; in many cases, only externally offered support and treatment can create the conditions in which their guidance systems can be gradually restored to proper working order.

Averting obesity and drug use also requires that, as a society, we take responsibility for the environments we create for young people. Instead of school cafeterias with an array of cheap, tempting foods high in calories and low in nutrients, we must expose young decision makers to food options that strengthen their health and resolve. Instead of stress-filled or empty time that promotes drug use, kids need access to appealing, healthy, and meaningful activities that encourage them to take pride in themselves and their behavior. Arming young people with scientific information about their bodies, brains, and the substances that can affect them is also crucial—which is the goal of National Drug Facts Week.

Obesity and drug abuse are medical issues, not moral failings. It is gratifying to present the converging science clearly showing this in a forum like TEDMED, composed of people who are informed and curious about the latest medical science. My hope is that the general public becomes more compassionate about these issues, supports wider access to treatment, and understands the importance of greater investment in research on the dynamic ways our brain can be changed by our behavior and vice versa.

Follow National Drug Facts Week 2015 news on Twitter @NIDAnews and on Facebook; or join the conversation by using: #DrugFacts.

Read my archived Facebook chat, held Thursday, February 12, 2015 at 1pm ET, hosted by TEDMED to find out what we can learn about compulsive overeating from studying the brain chemistry of people with drug addictions.

Nora Volkow

NIDA

Armando Pina