Cannabis damages young brains more than originally thought, study finds

By | December 20, 2009

Canadian teenagers are among the largest consumers of cannabis worldwide. The damaging effects of this illicit drug on young brains are worse than originally thought, according to new research by Dr. Gabriella Gobbi, a psychiatric researcher from the Research Institute of the McGill University Health Centre. The new study, published in Neurobiology of Disease, suggests that daily consumption of cannabis in teens can cause depression and anxiety, and have an irreversible long-term effect on the brain.

“We wanted to know what happens in the brains of teenagers when they use cannabis and whether they are more susceptible to its neurological effects than adults,” explained Dr. Gobbi, who is also a professor at McGill University. Her study points to an apparent action of cannabis on two important compounds in the brain — serotonin and norepinephrine — which are involved in the regulation of neurological functions such as mood control and anxiety.

“Teenagers who are exposed to cannabis have decreased serotonin transmission, which leads to mood disorders, as well as increased norepinephrine transmission, which leads to greater long-term susceptibility to stress,” Dr. Gobbi stated.

Previous epidemiological studies have shown how cannabis consumption can affect behaviour in some teenagers. “Our study is one of the first to focus on the neurobiological mechanisms at the root of this influence of cannabis on depression and anxiety in adolescents,” confirmed Dr. Gobbi. It is also the first study to demonstrate that cannabis consumption causes more serious damage during adolescence than adulthood.

via Cannabis damages young brains more than originally thought, study finds.

4 thoughts on “Cannabis damages young brains more than originally thought, study finds

  1. Neurofreak

    This PR blurb is amazingly disingenuous. The study was done on adolescent rats, not humans, and did not even involve marijuana, but instead a synthetic marijuana analogue that has both a higher for CB1 receptors than marijuana does, and also happens to be structurally quite different.

    This isn’t to say that theres anything wrong with rat studies, or that inferences can’t be made from chemical analogues but to say that “y causes x” is an oversimplification that comes pretty close to just being deceitful.

    I go into a little more elaborate detail about this study at my blog at

  2. Metamorphous

    Stay in school. Drugs is for fool. Don’t be a tool. Don’t do drugs. Do alcohol and cigarettes instead. You know, the taxed drugs 🙂 Very good for your health.

  3. The Necromancer

    Marijuana is a depressant, there’s no denying that. But it’s also a stimulus to creativity and has other positive side-effects. I’d be more worried about teenagers drinking. That’s brain-damaging. Heck, TV might be worst of all…

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