Study: Using Marijuana Can Make Teens Stupid – Permanently

A new study has concluded that teenagers who smoke pot suffer a significant drop in IQ that persists even if they stop smoking it later in life.

The article doesn’t explain why, except for this statement by lead researcher Madeline Meier of Duke University: “Parents should understand that their adolescents are particularly vulnerable.”

Well, there is an explanation.

During adolescence, a child’s brain experiences one final stage of brain development. It’s in the area called the prefrontal cortex (PFC), the part of the brain involved in “connecting the dots” – analysis, judgement, decision making and critical thinking. I sometimes refer to this as “the smart part of the brain,” because what it does makes us far more intelligent than any other animal species.

The PFC is located right behind the forehead. Like all other areas of the brain, development there starts with “blossoming,” when every brain cell there sprouts thousands of tiny connector fibers called dendrites. The connections that are used when the teen exercises critical thinking are reinforced. This causes permanent neural pathways to form, the kind of foundation wiring that gives a young person “a superior mind.”

But it’s “use it or lose it,” because at the end of adolescence, when the developmental window closes, the connections that weren’t used regularly are absorbed by the body and lost forever. What’s left is the permanent foundation for higher-level thinking.

This process – like any earlier phase of brain development – can be disrupted by the presence of alcohol or drugs. For this reason, doctors routinely warn expectant mothers that using cigarettes, alcohol or drugs during pregnancy can permanently damage the brain of the unborn child. After birth, small children typically don’t abuse alcohol or drugs, so more of this kind of brain damage during early childhood isn’t usually a problem.

But brain development isn’t over when teenagers begin experimenting with these substances. And the PFC, the area involved in the sensitive window of development during adolescence, happens to be the area most critically involved in intelligence. If a teen becomes a regular user, the “stupidity” effects won’t last just a few days. Getting high or drunk can cause disruption of normal brain development during a time when the foundation for critical thinking is under construction.

The potential consequences for what might otherwise seem like harmless fun are enormous. The “stupidity” could become permanent.

This is shocking, isn’t it? And very few parents know about this danger. And practically no teens.

But now you know. Is this information shocking enough to share with other parents?

My article about teen use of alcohol…

Teen use of pot is on the rise…

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2 Responses to Study: Using Marijuana Can Make Teens Stupid – Permanently

  1. Peter says:

    Alcohol and cannabis are two _very_ different substances. You’re misleading people by lumping their effects together as being the same.

    How do you reconcile the stud you cite in your post with the study was published this month, showing alcohol is far more harmful to children’s brains and finding cannabis leaves no change in the brain?: http://www.huffingtonpost.com/2012/12/21/teens-marijuana-brain-tissue-alcohol_n_2331779.html

  2. Peter, alcohol is probably more harmful, but during adolescence a sensitive window of brain development is underway, specifically the prefrontal cortex. The danger is that ANY form of alcohol or drug, if taken at the wrong time or in the wrong quantity risks perturbing this normal process. The fact that cannabis may be less harmful is no consolation. The goal is no harm at all, when it comes to permanent wiring of the part of the brain that is in charge of intellect and judgment. After adolescence the basic developmental period is over and these risks no longer apply.

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