Email this ArticlePrint This Page


  • Marijuana is not as harmless as many baby boomers once thought.
  • This drug can affect many vital organs.
  • Just as we are far more aware of the dangers of tobacco than we were when tobacco use became widespread, we now know more about the unhealthy effects of marijuana.

Among adolescents, marijuana use is second only to alcohol use. Many people believe that marijuana is harmless. They're wrong.

Marijuana affects the brain, lungs, heart and immune system. It can cause depression, memory loss and other cognitive problems. In the last half of 2003, according to the Drug Abuse Warning Network, marijuana was the third most commonly mentioned substance in drug-related hospital emergency department visits. In 2004, 11 percent of drug related emergency department visits involved marijuana.

"Marijuana is addictive," says Dr. Michael Dennis, an expert in adolescent addiction at the Chestnut Health Services in Illinois. "According to the American Psychiatric Association and the World Health Organization, it is one of the main substances that is recognized as meeting criteria for abuse and dependence, which are the clinical criteria for saying that something is addictive.

"Often, particularly baby boomers will feel like they're being hypocritical if they try to come down on marijuana use as dangerous," Dennis says, adding that many don't realize that evidence on the harmful effects of marijuana are "as strong as the evidence on tobacco was 20 years ago." What's more, as knowledge about marijuana's unhealthy side effects has grown, so has its potency. Marijuana smoked or ingested today is usually far stronger than the marijuana of a generation ago.