Marijuana

Info

To learn more about marijuana or obtain referrals 

to programs in your community, contact one of the 

following toll-free numbers:

SAMHSA’s Health Information Network 

1-877-SAMHSA-7 (1-877-726-4727)

(English and Spanish)

TTY 1-800-487-4889

The bottom line: If you know someone who 

smokes marijuana, urge him or her to stop or 

get help. If you’re smoking marijuana—stop! The 

longer you ignore the real facts, the more chances 

you take with your health and well-being. It’s 

never too late. Talk to your parents, a doctor, a 

counselor, a teacher, or another adult you trust.

Do it today!

Curious about the TV ads of the National Youth

Anti-Drug Media Campaign? Check out the Web site at

www.freevibe.com or visit the Office of National Drug

Control Policy Web site at www.whitehousedrugpolicy.gov.

 A& Q 

Q. Isn’t smoking marijuana less 

dangerous than smoking 

cigarettes?

A. No. It’s even worse. Five joints 

a day can be as harmful as 20 

cigarettes a day.10

Q. Can people become addicted 

to marijuana?

A. Yes. Research confirms you can 

become hooked on marijuana.

Q. Can marijuana be used as a 

medicine?

A. While the active ingredient 

in marijuana, THC, can be 

manufactured in a pill available 

by prescription to treat nausea 

and vomiting associated with 

certain cancer treatments, 

scientists say that more research 

needs to be done on its side 

effects and other potential 

medical uses.11
The Truth About Marijuana 

Slang—Weed, Pot, Grass, Reefer, Ganja, Mary Jane, Blunt, Joint, Roach, Nail

Get the Facts...

Marijuana affects your brain. THC (the active 

ingredient in marijuana) affects the nerve cells in the part 

of the brain where memories are formed. 

Marijuana affects your self-control. Marijuana can 

seriously affect your sense of time and your coordination, 

impacting things like driving. In 2005, nearly 242,200 

people were admitted to emergency rooms suffering from 

marijuana-related problems.1

Marijuana affects your lungs. Marijuana smoke 

deposits four times more tar in the lungs2 and contains 50 

percent to 70 percent more cancer-causing substances 

than tobacco smoke does.3

Marijuana affects other aspects of your health. 

Marijuana can limit your body’s ability to fight off 

infection. Heavy marijuana use also has been linked with 

depression, anxiety, and personality disturbances.4

Marijuana is not always what it seems. 

Marijuana can be laced with substances such as PCP, 

formaldehyde, or codeine cough syrup without your 

knowledge. “Blunts”—hollowed-out cigars filled with 

marijuana—sometimes have crack cocaine added.

Marijuana can be addictive. Not everyone who uses 

marijuana becomes addicted, but some users do develop 

signs of dependence. In 2006, nearly 290,000 people 

entered drug treatment programs to kick their marijuana 

habit.5

Before You Risk It...

Know the law. It is illegal to buy or sell marijuana. In 

most States, holding even small amounts of marijuana 

can lead to fines or arrest.

Get the facts. Smoking marijuana can cause health 

problems, such as chronic coughing, chest colds, lung 

infections, breathing problems, and cancer.6

Stay informed. It has not yet been proven that using 

marijuana leads to using other drugs, but most teens who 

try drugs start with marijuana, alcohol, or tobacco.7

 One 

study found that people who had used marijuana before 

the age of 17 were more likely to use other drugs and 

develop addiction problems later on.8

Know the risks. Marijuana affects your coordination 

and reaction time, raising your risk of injury or death from 

car crashes and other accidents.

Keep your edge. Marijuana affects your judgment, 

drains your motivation, and can make you feel anxious.

Look around you. Most teens aren’t smoking 

marijuana. According to a 2006 study, about four out 

of five 12- to 17-year-old youths had never even tried 

marijuana.9

Know the Signs...

How can you tell if a friend is using marijuana?

Sometimes it’s tough to tell. But there are signs you can 

look for. If your friend has one or more of the following 

warning signs, he or she may be using marijuana:

•	

•	

•	

•	

Seeming	dizzy	and	having	trouble	walking

Having	red,	bloodshot	eyes	and	smelly	hair	and	

clothes

Having	a	hard	time	remembering	things	that	just	

happened 

Acting	silly	for	no	apparent	reason	

What can you do to help someone who is 

using marijuana or other drugs? Be a real 

friend. Encourage your friend to seek professional 

help. For information and referrals, call SAMHSA’s 

Health Information Network at 1-877-SAMHSA-7 

(1-877-726-4727).

For more information or for references to facts found in this Tips for Teens, 

go to www.samhsa.gov/SHIN.

Revised in 2008.