What do we really know about smoking marijuana?

If you are a marijuana fan, you may think you are in luck as an increasing number of states legalize use of the drug. But a review of the past 20 years of research into marijuana offers a few cautionary principles you need to keep in mind if you indulge.

According to Wayne Hall, a World Health Organization adviser on addiction, two decades of investigations into the effects of marijuana has uncovered some well-documented risks as well as unanswered questions about its effects.

His review shows:

  • You basically cannot experience a fatal overdose of marijuana.
  • If you drive while stoned your risk of a car crash doubles. If you’ve also been drinking alcoholic beverages, the chances of an accident goes up even more.
  • Pregnant women who smoke marijuana give birth to smaller babies.
  • If you persistently use marijuana you run a 10 percent chance of developing dependence on it. About 16 percent of kids who start in their teens or early 20s become dependent.
  • Regularly using marijuana doubles your chances of having psychotic symptoms and problems, especially if you start smoking in your teenage years.
  • Kids who use cannabis have a greater chance of using other recreational drugs. But nobody knows if this is a cause-and-effect relationship.
  • Regularly smoking marijuana ups your risk of having chronic bronchitis.
  • If you are middle-aged and you smoke marijuana, you likely increase your chances of a heart attack.
  • If you use cannabis in your teens and into your 20s, you will probably lose a few points off your I.Q. Nobody knows if you can get them back by stopping your drug use.
  • Smoking marijuana may increase your risk of testicular cancer.

Hall’s report concludes: “…cannabis use increases the risk of accidents and can produce dependence, and …there are consistent associations between regular cannabis use and poor psychosocial outcomes and mental health in adulthood.”

Carl Lowe

By Carl Lowe

has written about health, fitness and nutrition for a wide range of publications including Prevention Magazine, Self Magazine and Time-Life Books. The author of more than a dozen books, he has been gluten-free since 2007.