Updated November 28, 2014.

These questions compiled by the National Institute on Drug Abuse are the most asked by teens concerning marijuana.

What is marijuana? Aren't there different kinds?
Aren't some forms of marijuana more potent that others?

How is marijuana used?
Is smoking it the only way it can be consumed?

How long does marijuana stay in the user's body?
The effects wear off quickly, but the metabolites linger.

How many teens smoke marijuana?
The answer may be surprising.

Why do young people use marijuana?
For what reason would kids start using illict drugs?

What happens if you smoke marijuana?
Several factors contribute to marijuana's effects.

What are the short-term effects of marijuana use?
The effects are not always predictable.

Does marijuana affect school, sports, or other activities?
Can your performance be affected by smoking weed?

What are the long-term effects of marijuana use?
Some long-term effects on health are known, others are suspected.

Does marijuana lead to the use of other drugs?
Is marijuana a "gateway drug" as it has been claimed?

How can you tell if someone has been using marijuana?
What are the signs of marijuana use?

Is marijuana sometimes used as a medicine?
If it's medicine, isn't it safe?

How does marijuana affect driving?
Does it affect response time and coordination?

If a woman is pregnant and smokes it, will marijuana hurt the baby?
Does it affect the unborn child?

What does marijuana do to the brain?
Which parts of the brain are affected?

Can people become addicted to marijuana?
Do people experience withdrawal symptoms?

What if a person wants to quit using the drug?
Are there any medications that will help?