Marijuana’s Effects On Young Brains

With the legalization of marijuana, it’s even more confusing for parents raising teens to guide them in whether to use pot. As an article in Sunday’s New York Times’ Education Life supplement indicates, mothers and fathers are taking a variety of stances, from “zero tolerance” to “outright permission.” But a study on the effects of marijuana, conducted jointly by Harvard and Northwestern University and published in The Journal of Neuroscience, demonstrates more profound and longer-lasting changes in the brains of young people, even casual users. Every parent needs to be aware of these findings:

  • Today’s pot is far more potent than what was used in studies conducted years ago
  • High-THC marijuana is associated with paranoia and psychosis (see my earlier blog on this finding)
  • Emergency room visits associated with adverse effects of marijuana use nearly doubled from 2004 to 2011
  • Higher potency intensifies addiction potential; for teenagers, the rate is one in six
  • Even light smokers showed abnormalities in the shape, density, and volume of both the nucleus accumbens (the brain structure at the core of motivation, pleasure, pain, and decision-making) and the amygdala (which processes emotions, memories, and fear responses)
  • These brain changes suggest THC’s disruption of focus, working memory, decision-making, and motivation may be longer-lasting than originally thought
  • The more individuals smoke, the greater the adverse effects of marijuana
  • One 2012 study found that teenagers who were dependent upon marijuana before age 18 and continued using it into adulthood lost an average of 8 IQ points by age 38
  • At Northwestern, subjects in the early 20’s who had stopped smoking for two years still had impaired working memory, which is a fundamental skill needed for learning

These neuroscientific findings may dispel common myths about marijuana and refute the harmless image of the smoking parents did themselves as teens. With the potent-THC content today, many more young people are at risk for addiction and brain changes that can impact their motivation, learning, and decision-making.

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