Questions about drugs--answers from scientists.

• Position: HEAPS UP: REAL NEWS ABOUT DRUGS AND YOUR BODY

Every year since 2007, scientists at the National Institute on Drug Abuse (NIDA) in Washington, D.C., dedicate a day to answering student questions about drugs. In this annual online chat-Drugs and Alcohol Chat Day*--teens across the country can ask the questions they most want answered, and scientists answer them. No judgment. Just the facts.

To read the actual questions and answers--more than 2,500--visit teens.drugabuse.gov/chatday2015. Here are a few Q&As inspired by Chat Day to give you some important facts now.

Q: SOME PEOPLE SAY MARIJUANA IS DANGEROUS AND OTHERS SAY IT'S NOT. WHATS THE TRUTH?

A: Scientific research has shown that marijuana can be dangerous for teens because their brains are still developing. Regular marijuana use may impact teens' ability to learn and even lower their IQs. It can also impair driving ability, especially when combined with alcohol. More recently, a lot of people have landed in the emergency room having psychotic episodes after eating food or candy containing marijuana. Not knowing that THC digests more slowly, they mistakenly eat multiple servings looking to increase or speed up the mind-altering effects.

Q: WHY DO PEOPLE USE TOBACCO WHEN THEY KNOW IT'S SO BAD FOR THEM?

A: It is bad for them! More than 480,000 people die every year from smoking-related illnesses. But people smoke because the nicotine in cigarettes is highly addictive. Young people are especially sensitive to nicotine's addictive effects, which is why most smokers get addicted before age 18. Some people mistakenly think that using a hookah (water pipe) will let them use tobacco but avoid the dangers of it. Not true. Hookah smoke contains the same chemicals as cigarette smoke and is also linked to heart disease and lung cancer. In fact, a typical hookah session can equal as many as 100 cigarettes.

Q: CAN COFFEE KILL YOU?

A: Caffeine is generally safe at levels found in beverages such as coffee, soda, or energy drinks--though drinking too much can make you feel sick. However, there have been overdoses from consuming caffeine powder. Just a teaspoon of it is equal to 25 cups of coffee--enough to kill you! Too much caffeine powder can cause fast and erratic heartbeat, seizures, vomiting, diarrhea, disorientation, and even death.

Q: HOW IS MARIJUANA ADDICTIVE?

A: Marijuana is addictive for some people, with the risk increasing for those who start using it as a teen. It affects certain receptors in the brain, called cannabinoid receptors...