Children's Hospital Colorado

Frequently Asked Questions About Marijuana

Q: What is marijuana?
A: Marijuana is the dried leaves and flowers of the cannabis plant, used for the variety of psychoactive (mind-altering) and physiological effects it has when consumed. Marijuana can be vaporized, eaten or smoked.

Q: Why do people smoke/ingest marijuana?

A: People smoke and ingest marijuana for many reasons: for fun, for a new experience, for medicinal purposes, or to cope with overwhelming emotions, to name a few. However, research has shown that marijuana use can have lasting negative effects on the developing brain (up to age 25), can lead to patterns of addiction, and is only a temporary aid to dealing with intense emotions.

Q: Is smoking/ingesting marijuana addictive?

A: Marijuana affects the brain’s reward pathways, and, according to the National Institute on Drug Abuse, long-term marijuana use can lead to addiction.

Q: Is there research to prove that marijuana has negative effects on the brain?
A: It is widely agreed that marijuana changes the structure of the developing brain (up to age 25). In fact, scientists are still discovering what marijuana will do to intelligence, memory and mental health. Recent studies include:

  • A 2010 study by researchers from the University of California San Diego and Yale University found that adolescent marijuana users exhibited poorer verbal learning, verbal working memory and attention accuracy than non-using adolescents. 
  • A 2012 study from the University of Wisconsin and the University of Cincinnati found that increased marijuana use in adults aged 18-26 was associated with slower psychomotor speed, more errors in cognitive inhibition and less efficient sustained attention.
  • A 2012 Duke University study found that persistent and adolescent-onset marijuana use is associated with a permanent decline in adult IQ by up to eight points.

Q: Does marijuana use cause schizophrenia?
A: We don’t know. While the vast majority of experts agree that marijuana has negative effects on young, developing brains (up to age 25), it is also widely acknowledged that more research is needed to fully understand those effects.

Emerging evidence shows that genes and family history of psychosis may have more to do with the development of schizophrenia than marijuana use. A recent report from Harvard University* cited research that suggests marijuana use could be associated with both earlier onset and more severe schizophrenic symptoms. The study emphasizes the need for more research on the topic.

*Harvard Research Study was published in Schizophrenia Research in December 2013. While discussing the results of this study, the researchers were careful not to declare the results as fact.

Q: What about children who have a legitimate need for medical marijuana?

A: It is possible that marijuana may help with certain medical conditions, although we need much more research on this topic to fully understand the link. Learn more about medical marijuana in Colorado.

Q: What about teens’ use of alcohol? Isn’t alcohol more dangerous than marijuana?
A: There will always be the issue of underage marijuana and/or alcohol consumption. Parents/caregivers must work to empower youth to make smart decisions when it comes to both alcohol and marijuana. Learn how to talk to kids about marijuana.

Q: What’s the difference between spice and marijuana?
A: “Spice” refers to a wide variety of herbal mixtures that produce experiences similar to marijuana (cannabis) and that are marketed as “safe,” legal alternatives to that drug. Sold under many names, including K2, fake weed, Yucatan Fire, Skunk, Moon Rocks, and others — and labeled “not for human consumption” — these products contain dried, shredded plant material and chemical additives that are responsible for their psychoactive (mind-altering) effects.

Sources: National Institute of Health/National Institute on Drug Abuse, New England Journal of Medicine, Colorado Department of Public Health and Environment, and Colorado’s “Don’t Be a Lab Rat” campaign aimed to increase the perception of risk among youth regarding underage marijuana use.