Effects of Drugs on the Teen Brain

Teens Ask, Hazelden Betty Ford's Prevention Solutions Answers
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Use of any addictive substance can be risky and comes with consequences.

Teens are curious about the role their brain plays in alcohol and other drug use and addiction. In this second installment of "Teens Ask, Prevention Solutions Answers," we asked for the help of students in some of our client schools in order to share what is on teens' minds when it comes to their brains. Want to catch up? Read the first installment.

These are the students' insightful questions, and Prevention Solution's answers:

Q: Once Inside a Teen's Body, What Do Alcohol and other Drugs Actually Do to the Teen Brain?

A: All addictive substances affect the reward pathway of the brain, through which teens are highly motivated. Alcohol and other addictive drugs increase the number of reward-related chemicals in the brain. For instance, these substances flood the brain with a chemical called dopamine. This chemical flood can result in feelings of euphoria, relaxation, and relief from stress.

Dopamine is an interesting chemical. Think of those times you've laughed until you've cried or lost your breath. That's dopamine at work. But despite the fact that dopamine causes pleasure, its true job is not to make people feel good. Its real job is to drive a human to continue survival-related behavior, like sleeping and eating, and to encourage pro-social behavior, like forming bonds of friendship.

What makes addictive substances so risky is that their effects override the natural and healthy messages of the human brain. When alcohol and other drugs unnaturally increase dopamine in the teen brain, the using teen gets the message, "you don't need food or sleep or friendships as much as you need alcohol and other drugs."

What was once a healthily functioning survival mechanism of the reward pathway becomes a broken tool, damaged by repetitive substance use to create addiction.

Q: How Do Different Substances Act in the Brain?

A: Substances often fit into three categories: stimulants, depressants, and hallucinogens:


Stimulants excite, or speed up, the brain and its functions. Use of stimulants can cause increased energy, faster breathing, more rapid heart rate, and higher body temperature.


Depressants inhibit, or slow down, the brain and body. Use of depressants can cause lowered energy, slowed breathing, slowed heart rate, and lower body temperature.


Hallucinogens impair the brain and body's perception of reality. Use of hallucinogens can cause delusional thoughts, bizarre physical motions, and the experience of sights, sounds, tastes, and sensations that are not there.

Q: What's the Difference Between the Teen and Adult Brain When it Comes to Alcohol and Other Drug Use?

A: Brain cells, called neurons, are generally covered and protected with a fatty substance called myelin. This myelin acts like an insulator, helping brain messages to travel from neuron to neuron, cell to cell, like electricity flowing through a series of telephone wires.

While the neurons in an adult brain are well myelinated, and well protected, the maturing neurons in a teen brain have more "myelination" to undergo.

Since teen brains are "in progress" in this way, teen brain cells send "louder" messages to one another than do adult brain cells, in much the same way that an identical song is broadcast much less attractively through a cheap speaker than it is through a highly-sophisticated sound system.

Through these more intense, less refined brain messages back and forth, teens actually experience more intense sensations of pleasure from enjoyable activities than do adults. They also experience negative emotions—like anxiety, stress, and depression—more "loudly." This means that teens may crave the alleviation of negative emotions more urgently than adults, because these emotions are truly felt more deeply.

It also means that when teens engage in risky behaviors like alcohol and other drug use, the reward pathway of the teen brain is highly sensitive to substances' effects.

Q: Which Substances Are Associated with Long-Term Effects, and What Are these Effects?

A: Use of any addictive substance can be risky and comes with consequences. Long-term effects are not the only consequences! Instead, long-term effects happen after substance use has already caused plenty of other negative consequences for teens.

So when considering long-term consequences, remember that immediate and short-term consequences happen first, and can be equally devastating to a teen's life. It is important to intervene on teenage use of alcohol or other drugs as soon as you notice any risk or consequence.

If someone is suffering from the long-term physiological effects of alcohol or other drug use, he has likely continued with problem use in spite of humiliating experiences, relationship difficulties, and other health and social consequences.

The long-term effects of alcohol misuse include:

  • Liver damage
  • Heart problems
  • Beer belly
  • Physical dependence on alcohol, producing other dangerous health conditions.

Tobacco use also produces long-term effects, including:

  • Cancer
  • Emphysema
  • Reduced lung capacity, if smoked
  • Blackened or yellowed teeth
  • Early wrinkle formation

The long-term effects of marijuana are less well-known by many students and are the subject of continuing study in the scientific community.

Some long-term effects of chronic marijuana use, however, are clear:

  • Impaired problem solving
  • Arrested emotional development
  • Difficulty with memory recall
  • Disruptive, chronic, and persistent lack of motivation
  • Increased risk of mood disorders (e.g., major depressive disorder)
  • Increased risk of anxiety disorders (e.g., generalized anxiety disorder)
  • Increased risk of psychotic disorders (e.g., schizophrenia)

Given the teen brain's unique vulnerability to substance use and addiction, it is extremely important that teens learn about the immediate, short-term, and long-term consequences of any substance use.

Substance Abuse In Adolescence

Adolescence may be challenging, but the teen brain is up to the task. A teen brain will flex, adapt, and grow in ways an adult brain cannot. The creative, engaging questions posed to Prevention Solutions by our students are great examples!

While teens are constantly preparing to meet the challenges of an adult world, and taking some risks during this time is natural. Still, making too many risky decisions in the teen years while the may throw off the course of healthy brain development in ways that add an undue burden.

Using substances as a response to peer pressure is one such risky decision. This kind of use actually makes healthy personality development harder. Alleviating particularly intense negative emotions through over-stimulation of an already sensitive reward pathway is another risky choice. Use in this way it damages the brain, predisposes teens to addiction, and makes having healthy fun more difficult.

Learning to meet challenges, make healthy decisions, and have healthy fun can be exceptionally rewarding for growing teens. If teens take very good care of their brains during adolescence, their brains will continue to take very good care of them for the rest of their lives!

Bava, S., & Tapert, S.F. (2010). Adolescent brain development and the risk for alcohol and other drug problems. Neuropsychology Review, 20(4), 398-413. doi: 10.1007/s11065-010-9146-6.

Berger, K.S. (2011). The Developing Person Through the Life Span (8th ed.). New York, NY: Worth Publishers.

Clark, D.B., Thatcher, D.L., & Tapert, S.F. (2008). Alcohol, psychological dysregulation, and adolescent brain development. Alcoholism, Clinical and Experimental Research, 32(3), 375-385. doi: 10.1111/j.1530-0277.2007.00601.x.

Romer, D. (2010). Adolescent risk taking, impulsivity, and brain development: Implications for prevention. Developmental Psychobiology, 52(3), 263-276. doi: 10.1002/dev.20442.

Rotzinger, S., Bush, D.E., & Vaccarino, F.J. (2002). Cholecystokinin modulation of mesolimbic dopamine function: Regulation of motivated behavior. Pharmacology & Toxicology, 91(6), 404-413. PMID: 12688386.

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