How drugs affect the teenage brain

Before reading this, please refer to the previous blog post to understand the brain terms we will be using, and how drugs affect the brain in general. 

There are two important ways in which the teenage brain is uniquely sensitive to and affected by drug use. 

1) During adolescence, the midbrain (the area responsible for reward and motivation, which is profoundly influenced by certain drugs) is well developed, but the prefrontal cortex (the rational part of the brain) is the last area of the brain to develop. As a result, pleasure and emotion—not reasoning—guide most teen behavior.This means teens are more prone than adults to engage in risk-taking behaviors. Their impulses are very powerful, while their ability to control those impulses is not quite as strong.

2) Drugs have an increased impact on the teenage brain, as compared to adults. During adolescence the brain is developing at a rapid rate. Excess grey matter is pruned out, making brain connections more specialized and efficient, which results in a more skilled and well functioning brain. This pruning process is changed by persistent substance use. fMRI machines show altered grey and white matter in the brains of adolescents using substances.

How does this affect the adolescent? Research has shown that certain substances used persistently in adolescence result in a decline in cognitive ability: impaired problem solving; arrested emotional development; difficulty with memory recall; disruptive, chronic, and persistent lack of motivation; increased risk of mental health disorders (other than addiction), including mood disorders, anxiety disorders, and psychotic disorders.

According to research, the earlier an adolescent began using substances, the higher the risk of developing a substance use disorder. Cognitive decline related to substance use is worse for people who started before 18 years old. These cognitive changes persisted even when the adolescent did not use for at least a year

If you are a parent…. DON’T PANIC!

These studies were done on teens with persistent, chronic substance use. The effects of drug use are mitigated by environment, extent of use, and other predisposing factors. Most of us experimented with drugs in our teens, and most of us turned out okay. Not only that, but rates of teen drug use have dropped since the 90s! (Internet addiction has gone up, but that’s a blog post for later….)

Share information rather than just rules

Teach your teens about the critical period they are in with respect to their brain development, how this could impact their response to peer pressure and risky situations, and how this makes their brain more vulnerable to the negative long term effects of substances if used persistently. Encourage them to delay substance use as long as possible to reduce their risk of substance use disorders and cognitive deficiencies. Teach them about healthy ways of reducing and coping with stress and peer pressure.

Pay attention to how you lead by example: if you tell your teen to practice healthier ways of coping with stress but then they see you go straight for a glass of wine after a rough day at work…

Well, you see where this is going.

If you are concerned that your teenager may have a problem with substance use already, share your concerns in a calm, open-minded way, and invite them to share any questions or concerns with you. Try to arrange an evaluation by their doctor, who can help determine the extent of the problem and direct you to helpful resources.

Most importantly, when speaking with your teens, keep the conversation neutral and nonjudgemental. Adolescent are curious, and curiosity is important for their developing brain. Share information, rather than just rules, with them. This will help them better understand themselves and their environment, and exercise appropriate caution and sensibility as they develop their independence and explore their world.

How to talk to your kids about drugs (so that they actually listen)

According to  a recent Canadian Study, one in four students between grades 7-12 were offered drugs in the past year, and 1 in 6 of them had been offered, sold, or given drugs in school. The average age that drug use begins is 15.7 years old.

While this is distressing to parents, it is also an opportunity. You are a role model for your kids, and your views on alcohol, tobacco, and drugs can strongly influence how they think about them. It is critical that we help our children navigate this challenging time and arm them with information and support.



Many people find talking about drugs with their kids uncomfortable, and either take a black and white stance (i.e. all drugs are bad, “Just Say No”), or skirt the topic altogether. Concerns about planting ideas in a child’s head, being seen as a hypocrite (i.e. because you smoke/drink), or the anxiety caused by discussing something you’d prefer to not think about, are some reasons why parents avoid the conversation.

Let me reassure you. Having a discussion with your kid about drugs will not make them a drug user. And using drugs yourself is not a reason to avoid discussing them. In fact, your child will probably appreciate or feel more comfortable if you share your experience, what made you use, and the consequences/challenges you have experienced related to your use/dependence.

Here’s the key: It’s less important what you say and more important how you say it.

You and your kids can find lots of specific drug information online. The goal is for your child to feel comfortable talking to you about their experiences, questions, and concerns around drugs. To see you as a reliable and trusted resource. Because when kids don’t feel comfortable talking to parents, they seek answers elsewhere. And kids who are not properly informed are at greater risk.

Ways to help your child feel comfortable:

  • Encourage honesty, be curious and nonjudgmental. Consider why your child/ their friends might be tempted to use drugs (thrill-seeking, boredom, peer pressure), and explore alternate, safer ways to achieve those goals.
  • Discuss the risks honestly, based on evidence,  not exaggeration (if you tell your kids drugs will fry their brains, but they see their friends using drugs and still functioning well, they won’t trust you as a reliable resource).
  • If your child asks you a question that you don’t know the answer to, be honest. You can get back to them, or research the answer together.
  • Finally, remember that this is not a one-time lecture, but rather an ongoing conversation. Our children change every year, and the risks and pressures of last year may be completely different the following one. Let your child know that the door is always open to talk more.

Having open hearted, two-way conversations will help your kid see you as a resource they can turn to. We may not always like what we hear, but we have a better chance of keeping our children safe if we are included in the conversation.