Differences in the brain structure of adult and teen brains contribute to risky teen behavior, including substance use.

The teen years are a time for major changes. Teen bodies, abilities and attitudes all seem to change at a whirlwind pace. The brain also undergoes major changes in the teen years. Unfortunately, some brain changes may put teens more at risk of drug use. Worse yet, because they have an undeveloped brain, teens may minimize the risks they face from drug use.

The Adolescent Brain

Although some teens may look like adults on the outside, on the inside, it is a different story. In particular, teen brains are different from adult brains. An adult brain has more highly developed brain cells and areas than teen brains. Some of the differences between teen and adult brains include:

  • Prefrontal Cortex: This area of the brain’s frontal lobe helps you think before you act and does not fully mature until you are in your 20s. As a result, teens do not have a fully developed prefrontal cortex. Instead, their brains react based on an area of the brain called the amygdala, which causes emotional, impulsive reactions. The amygdala matures during childhood, much earlier in life than the prefrontal cortex.
  • Extra Brain Cells: The teen years are a period of what is called neuroplasticity. The brain is malleable, and during this time, it develops extra cells to help teens learn new skills. However, a side effect is that the brain does not process information efficiently in these cells. In turn, teen decision-making skills are harmed.
  • Brain Cell Connections: The links between brain cells that help them communicate quickly do not fully develop until adulthood. Therefore, teens have a hard time getting signals from their prefrontal cortex to the rest of their brain in time to override emotional reactions from their amygdala.

Due to these brain differences with adults, the teen brain has been compared to a car with a gas pedal that works well and brakes that do not. 

The results of the differences between adolescent and adult brains often show up in teen behavior:

  • Instant Gratification: Studies have shown that drug use and risk-taking is linked to the teen desire for instant gratification. Doctors think that high levels of the brain chemical dopamine are responsible. Further, this drive for instant gratification is linked to the brain’s reward system, which is also involved in drug use and addiction.
  • Impulse Control: The areas of the brain that respond to pleasure and pain are mature in teens and can cause impulsive behavior. Unfortunately, these parts of the brain are also linked to drug use.
  • The Teenage Invincibility Theory: Research shows that teens often think about what they like about drug use, focusing on how a high feels good, and do not think that bad things like overdose will happen to them. This feeling of invincibility may be particularly powerful if the teen has been able to use drugs before without overdosing.

How Teen Invincibility Contributes to Teen Drug Use

Teens who think they won’t face consequences for risky actions are mistaken. Overdose deaths in teens have climbed, along with overdose deaths in the rest of the population. Because of their undeveloped prefrontal cortex, teens are at risk for bad decision making about drugs. Worse yet, teen drug use and drinking further delay teen brain development. The lack of a mature brain impacts teen behavior in several ways, like:

  • Inability to Assess Risks: Teens are less able to assess risk than adults, especially when it comes to substance use. For example, while nearly 73% of Americans know that smoking is dangerous to health, far fewer teens perceive this risk.
  • Inability to Recognize Future Consequences: Teens often struggle with abstract thinking, such as imagining the future. Therefore, it can be hard for a teen to imagine the long-term consequences of drugs they take today. Using examples of long-term harm from drug use may not work to stop teen drug use. Instead, using short-term examples of harm from drugs may be more helpful in stopping teens from using drugs. For example, telling teens that smoking can lead to cancer later in life is an abstract concept. However, telling them that smoking can discolor their teeth and give them bad breath is a short-term consequence they can more easily imagine.
  • Lack of Inhibitions: As teens age, studies suggest that their brains start to rewire to become more social. In turn, teens can become disinhibited, especially around their friends. A part of the brain called the ventral striatum is active in teens when they are around their peers. Doctors think this part of the brain may work with the amygdala in promoting teen response to social activity, like peer pressure. The amygdala and the ventral striatum make teens more likely to respond to social cues than to their underdeveloped prefrontal cortex when making decisions.
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Editor – Megan Hull
Megan Hull is a content specialist who edits, writes and ideates content to help people find recovery. Read more
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Medically Reviewed By – Dr. Jessica Pyhtila, PharmD
Dr. Jessica Pyhtila is a Clinical Pharmacy Specialist based in Baltimore, Maryland with practice sites in inpatient palliative care and outpatient primary care at the Department of Veteran Affairs. Read more

American Academy of Child & Adolescent Psychiatry. “Teen Brain: Behavior, Problem Solving, and Decision Making.” September 2016. Accessed July 27, 2019.

Wickman, ME, et al. “The Adolescent Perception of Invincibili[…]Promotion Strategies.” Journal of Pediatric Nursing, December 2008. Accessed July 27, 2019.

University of Michigan Health System. “How Adolescent Thinking Develops.” December 12, 2018. Accessed July 27, 2019.

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Substance Abuse and Mental Health Services Administration. “Trends in Perception of Risk and Availab[…]ime College Students.” August 16, 2016. Accessed July 27, 2019.

National Institute on Drug Abuse. “Principles of Adolescent Substance Use Disorder Treatment: A Research-Based Guide.” January 2014. Accessed July 28, 2019.

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Centers for Disease Control and Prevention. “Drug Overdose Deaths in the United States, 1999–2017.” November 2018. Accessed July 28, 2019.

Medical Disclaimer

The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.