Marijuana: Not as Harmless as Some Teens Think

Marijuana: Not as Harmless as Some Teens Think

Researchers at the University of Michigan did their yearly Monitoring the Future survey of 8th, 10th and 12th graders. The survey was carried out in classrooms around the country earlier in 2012 under a grant from the National Institute on Drug Abuse (NIDA). The survey included 45,449 students from 395 public and private schools around the country. The survey showed the followed:

  • 12th graders: 6.5% said they smoke marijuana daily, up from 5.1% in 2007. Nearly 23% said they smoked marijuana in the month prior to the survey. Just over 36% said they smoked marijuana within the previous year.
  • 10th graders: 3.5% said they use marijuana daily. 17% reported use during the past month and 28% reported use in the past year.
  • 8th graders: 1.1% reported daily use. 6.5% reported past month use and more than 11% said they used marijuana in the past year.

Another interesting find is that teen’s perception of how harmful marijuana can be is down. One concern with this perception is that it could mean an increase in future use of the drug. Only 41.7% of 8th graders see occasional use of marijuana as harmful and 66.9% see regular use as harmful. Both rates are at the lowest since this survey was started in 1991. And as teens get older, the perception of risk goes down further. Only 20.6% of 12th graders see occasional use as harmful (the lowest since 1983) and 44.1% see regular use as harmful (the lowest since 1979).

So what are some concerns with teen marijuana use? One big concern is the link the between prolonged marijuana use and cognitive or neural impairment. A 38-year NIH-funded study, published in 2012 in the Proceedings of the National Academy of Sciences, showed the following:

  • People who use marijuana heavily in their teens and continued through adulthood showed a significant drop in IQ between the ages of 13 and 38 – an average of 8 points for those who met criteria for cannabis dependence.
  • Those who used marijuana heavily before age 18 (when the brain is still developing) showed impaired mental abilities even after they stopped using the drug.

What are some other concerns?

  • THC, a key ingredient in marijuana, alters the ability of the hippocampus, a brain area related to learning and memory, to communicate effectively with other areas of the brain. So there is concern that regular or daily use of marijuana will get in the way of teens and young people being able to reach their full potential to do well in school or in other areas of their lives.
  • In one study, heavy marijuana abusers reported that the drug impaired several important measures of well-being and life achievement, including physical and mental health, cognitive abilities, social life, and career status.
  • Marijuana use that begins in adolescence increases the risk for addiction. The risk of addiction goes from about 1 in 11 overall to about 1 in 6 for those who start using in their teens, and even higher among daily smokers.

Marijuana might be seen by many as a relatively harmless drug. However, teens buying into that perception are probably missing valuable information on what the short- and long-term effects of marijuana use are – particularly for those using marijuana regularly. For more information on marijuana, including the short- and long-term effects of using marijuana and what to do if you want to stop using marijuana, go to the NIDA For Teens webpage Facts on Drugs: Marijuana.