These questions were answered by more than 50 individual scientists and science writers with expertise in addiction. To get as many answered as possible, responses were written quickly based on the personal background and knowledge of each expert. Please note that there was not a secondary review or proofreading of each fact, and if readers have questions or comments about any response, they can ask further questions.

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<span style="font-size: 0.9em;">what is the difference between chewing tobacco and smoking/ do they doth cause the same problems</span>

-24468, Maryland
Each day in the United States, more than 1,200 youth under age 18 use smokeless tobacco for the first time (including chewing tobacco or snuff). More than 1,200 people die each day in the United States because of cigarette use – that is nearly 1 person every minute!  Each contain poisonous chemicals and can cause similar problems, such as cancer.  
  • Chewing tobacco and snuff contain 28 carcinogens (cancer–causing agents).
  • Smokeless tobacco increases the risk for cancer of the oral cavity, which can include cancer of the lip, tongue, cheeks, gums, and the floor and roof of the mouth.
  • Other effects include oral leukoplakia (white mouth lesions that can become cancerous), gum disease, and gum recession (when the gum pulls away from the teeth).
  • Possible increased risks for heart disease, diabetes, and reproductive problems are being studied.
-Joni Rutter

a realy close friend of mine OD on Heroine and i was wondering how Heroine kills.

-JMCBowers, Maryland
I am sorry to hear that JMC,
It is a real tragically that occurs way too often.  I hope you are doing ok.
Heroin affects regions of the brain that regulate breathing.  When a person takes too much, it can slow their breathing to the point where it just stops.  Basically, they go to sleep, breath less and less, until they stop breathing and die.   Again, I'm so sorry to hear about your friend.  Here's more information on heroin at -
-Dave Thomas

a student wants to know...How can you tell if people smoke weed?

-c322d, California

Well--there's a distinctive smell to the smoke if you happen to be around the person shortly after they've smoked, but if not-- they may be acting silly, have trouble remembering what they just said or did, have slowed reaction time or poorer coordination (in sports, for example). 

-Susan Weiss

About how many people die from drug related causes?

-HappyCows42, Massachusetts

Hey HappyCows42. Hope you're staying warm up there in Newton! According to the Centers for Disease Control and Prevention, 38,329 Americans died from overdoses in 2010. About 60 percent of those (22,134) involved prescription drugs, and 3/4 of those were opioids like oxycodone and hydrocodone. (Opioids are painkillers made from the same stuff as heroin.) For Massachusetts, the overdose death rate for prescription drugs was between 9.5 and 12.3 persons per every 100,000 people in 2008. It's important to remember that overdose deaths can be prevented. If you're around someone who might be experiencing an overdose, call 911 immediately. But you don't have to wait until then to get help. If you want to ask about getting substance abuse or mental health treatment, call 1-800-662-HELP, 24/7. Or you can go to to find information about treatment centers in your area.

-Marsha Lopez

about how many people do drugs

-midnight, Maryland
Hi there midnight! Good question! There are several national surveys that are done annually to determine how many folks use drugs. For example, the Monitoring the Future (MTF) Survey collects information from 8th, 10th and 12 graders. According to this survey, approximately 28% of 8th, 10th and 12th graders combined used an illicit substance in the past year. Another survey, the National Survey on Drug Use and Health (NSDUH), surveys persons aged 12 or older. According to NSDUH, about 24 million people (or about 12% of adults) aged 26 or older, used an illicit drug in the past year.  I hope this helps! 
-Geetha Subramaniam

about how many smoke in the world

-ANDREW2001, Maryland

Hey there ANDREW2001. The short answer is too many! Estimates now put the number at about 1 billion (with a B!). But it's hard to figure out just how many people are smoking--or using any other harmful tobacco products, like hookahs and cigars. But we do know what the consequences look like. According to the World Health Organization, upwards of 6 million people die every year because of tobacco use. That's more than the entire population of Maryland, where you're writing from! Here in the United States, about 43 million people smoke (according to the Centers for Disease Control and Prevention), and close to 440,000 Americans die every year because of tobacco use. Around 15 percent of American high school seniors reported smoking cigarettes in the past 30 days, too (according to the 2013 Monitoring the Future Study). So if you're a smoker or if you use other tobacco products regularly (like chew, skoal, cigars, or hookah), or if you know someone who is, consider quitting! It could save your life.  Information about smoking and prevention can be found at, or FDA:

-Marsha Lopez

Are steroids the only drugs that enhance athletic abilities?

-RrRrRayG, Maryland
Hey RRRRRay,
Anabolic steroids are not the only chemicals used to enhance performance.  For example, testosterone, stimulants, pain killers, diuretics, blood boosters and other drugs are used.  As a sports fan, I think it is a real shame, for the athletes and the sports.   
-Dave Thomas

Are students starting to get more creative with things they ingest?

-gem, New Jersey

i don't know if students are getting more creative--but drug makers are.  they are coming up with new and dangerous chemicals (like bath salts and spice) to make money, without concern about the consequences.

-Susan Weiss

Are teenagers more likely to do drugs than adults?

-kerstin, Massachusetts
Hi, Kerstin, thanks for your question!  According to the 2012 National Survey on Drug Use and Health, there are more than two times as many 18-25 year olds using drugs than 12-17 year olds (21% vs. 9.5%). So I would definitely say young adults are more likely to do drugs. While that's not good at all, it is better than the other way around because science has shown that the earlier a person starts using drugs the more likely s/he is to get addicted and suffer major social and medical problems. 
To learn more about the health effects of drugs, visit NIDA’s teen site here:
-Marsha Lopez

Are testosterone pills and certain performance supplemants just as dangerous as drugs such as tabacco, cocaine, etc.

-joeyAbagahuh, New York

Testosterone and other supplements used in doping can really affect your normal development. Testosterone is a hormone and important to your normal development. It can really mess up your normal growth and maturation. You realize that this is such an important time in your life- why let any drug mess that up. Of course tobacco and cocaine and other illegal drugs have important affects on your body and your health too, but they are different than those caused by testosterone. All are harmful to you but in different ways. This is why many of the major sports organizations are imposing bans on these substances.

-Marilyn Huestis

Are Texans more likely to Drink &amp; Drive compared to any other state?

-Lime, Texas

Texas is Ranked #11 in the United States for rates of drunk driving. Be careful out there!

-Aaron White

are the affects for drinking alcohol different for youths and adults?

-puppylover123, Maryland

Teens who drink face many of the same risks as adults who drink - but teens face additional risks including negative effects on brain development and an increased risk of developing alcohol problems later in life. Risks facing anyone who drinks too much include: 

  1. Legal trouble
  2. Car crashes and other accidents
  3. Making bad choices and engaging in risky behavior

Research tells us that drinking lots of alcohol during the teenage years can make the area of the brain called the frontal lobes smaller. The frontal lobes help us make decisions, think about things and pay attention. Teenagers who drink a lot have problems with these things. Alcohol also can shrink the hippocampus, the area of the brain area that helps us learn and remember things. Teenagers who drink a lot also have trouble with learning. We do not know yet whether these problems go away if the teenager stops drinking.

Drinking at a young age makes it much more likely a person will develop alcoholism later in life. It's really important to wait as long as possible to drink alcohol, or to avoid it altogether. Check out:

-Aaron White

Are the drugs that are advertised on TV for medication purposes safe with all the side effect possibilities?

-ryan_thorpe, New York
Hey Ryan, one general fact is that all drugs and medications have side effects.  When taken as they are prescribed, the possibilities for harm and side effects are minimized.  If you want more information about the health effects of drugs of abuse, check out
Thanks for writing in! 
-Joe Frascella

Are the effects of drugs different for teens than for adults?

-Meg7, Massachusetts
Hello meg7
what a great question.
the short answer is a resounding yes!!!
the brain is like a computer. During adolescence your computer is being actively programmed, so when you use drugs they introduce glitches in the program that can persist and affect the program (behaviors) long into the future. In contrast, when an adult uses a drug it affects a program that has already been written long ago, so the glitches are mostly temporary.
Hope this helps. Stay strong and healthy.
-Ruben Baler

Are the effects of marijuana different on men and wome?

-Rinee3236, Massachusetts

We are still learning about that, but its a very interesting question because we know that marijuana acts on the endocrine (or hormonal) systems.  It can have effects on fertility, sperm count, and has been linked in at least one study with a severe form of testicular cancer.  But, its effects on the brain have not yet been distinguished between men and women.  In general, males are heavier users and thus more likely to get addicted, but that may change as societal norms change.   

-Susan Weiss

Are the same kind of drugs used in other parts of the world or do they have different ones?

-Dude, Maryland

Hey Dude. Great question! Generally speaking, different regions of the world use drugs at different rates, just like the United States has regional differences in use. Some parts of the world experience types of drug use results because they come from plants that are specific to certain regions of the world. For example the chewing of betel nut, grown in tropical Pacific, Asia, and parts of east Africa. That said, some drugs unfortunately appear in most places around the globe. Marijuana, cocaine, heroin, alcohol, tobacco, and ecstasy are some of the most common ones. Check out this interactive map the Guardian newspaper put together using United Nations data. But remember: drugs down the street or on the other side of the planet have the same bad effects on your health and your life. So choose abide by a healthy lifestyle and stay off drugs, Dude!

-Marsha Lopez

Are there any drugs that are not Addictive?

-WaffleKing, Maryland
Great question, WaffleKing!  Most abused drugs are very addictive, but there are some, such as some of the hallucinogens for which addictive properties have not been shown.  That said, everyone's response to drugs is unpredictable; just because someone may abuse some drug and not become addicted, it does not mean that for someone else, taking a drug a few times might not lead to addiction.
For more information on addiction, check out:
-Joe Frascella

Are there any drugs that are typically considered illegal that can be prescribed by doctors?

-beginagain, New York

Hi beginagain - generally definition drugs that can be prescribed by doctors are not illegal.  The one exception to that is marijuana which is legal under some states' laws but still illegal under Federal law. Great question!

-Steve Gust

Are there any good side effects of drugs?

-heresjohnny123, Maryland
Hello heresjohnny123,
This is a good question. Some of the drugs that are abused by youth and adults do have some therapeutic effects, or at least potentially. For example prescription opioids have a clear benefit and provide great short-term pain relief after someone has had surgery, accidents, etc. They also help treat chronic pain that often accompanies cancer. Certain derivatives of marijuana plant have been found to be helpful in reducing nausea that can occur during cancer or HIV treatments. Despite what you read in the papers, street drugs (i.e. the ones that are illicit and not prescribed by a doctor) are not considered therapeutic or helpful in improving the health of individuals.
thanks for asking! 
-Geetha Subramaniam

Are there any hallucinogens that can be placed into an aerosol can? If so, are they dangerous?

-ThleduinAlkara, Pennsylvania
Hi ThleduinAlkara,
I've never heard of hallucinogens that you can put in an aerosol can! Good question. Definitely don't sniff anything from an aerosol can--it can be really dangerous.
-Eric Wargo

Are there any medical uses for marijuana? If so how many?

-heresjohnny123, Maryland

Great question, heresjohnny123!  Yes, THC, the active drug in marijuana has been shown to have medicinal effects...for example, it helps in nausea, relieving the pressure in one's eyes with glaucoma, used for pain, and I am sure there are other medicinal properties still to be discovered.  NIDA supports research to create medicines using THC and other chemicals.  The problem with using smoked marijuana is that there is no dosage control. Here's a link to the NIDA teen site fact sheet on marijuana:

-Joe Frascella

Are there any positive effects for smoking weed?

-anonymous, California

Great question. Its one that's being debated everywhere. Some states have legalized its use for medical purposed but the FDA has not approved it as medicine. More research is needed though we suspect that some of theTh chemical components of the cannabis plant will be what's most therapeutic. Thanks!

-Jack Stein

Are there any proven negative effects of the coca plant?

-walterjohnson, Maryland

Hey WJ, good question. The answer is yes. Many drugs come from chemicals that exist naturally in plants. Cocaine is derived from coca leaves.  We know that cocaine can produce several short-term adverse effects such as dilated pupils, vasoconstriction, elevated body temperature and increased heart rate. It can even, in rare instances, lead to death.  Find out more about the effects of cocaine and other drugs of abuse at

-Kris Bough

are there any safe drugs that can give you a high

-jd, New York

No safe drugs that we know of, but there are activities you can do that increase dopamine and make you feel good, like going out with friends, exercising, listening to music.  

-Nora Volkow

Are there any substances that people use daily, but don't know they actually contain drugs?

-sandy20, New York

Hi Sandy - this is difficult to answer without knowing the specific substance you are talking about.  However, several possible examples are various herbal products that are available online.  We do not know what many, or most, of these products actually contain.  There are also products out there like bath salts and spice which have drugs sprayed onto them. If you have any doubts or questions the best thing to do is to avoid taking them.  

-Steve Gust

Are there certain drugs that target only certain parts of the brain? For example, cocaine affects dopamine and the limbic system.

-UNIV NorthTexas, Texas

Great question!  The fact that drugs only work on certain parts of the brain (or other parts of the body) is a cornerstone of pharmacology (the study of drugs).   Whether a drugs affects the nerve cells in a certain part of the brain depends on whether the cell contains a protein called a receptor that the drug can attach to.  Receptors have a specific shape and drugs have to have the same shape to fit into the receptor.  Once a drug attaches to a receptor, a sequence of biochemical events are triggered than change the function or even the structure of the nerve cell, and even other nerve cells connected to the initial nerve cell.  So in principle all drug target only certain parts of the brain that contain the proper receptors.  Which parts of brain have those receptors is partly a function of genetics and partly a function of the brain's development and adaptation to events in the environment. Hope this helps.  You can find out more about drugs and receptors at

-Steve Grant

Are there drugs that people take to become less stressed?

-annie, Hawaii

annie: Hello there! Thanks for your question - and the short answer is 'yes.' However, the best answer is to ask you about the source of your stress - school, home, friends. Ideally you want to find solutions to deal with the stress without considering medications. Stress is a normal reaction and sometimes can be beneficial in certain situations. This way, you can solve your way out of many problems on your own, and you might come up with some amazing, creative solutions. If you really think you might benefit from taking medications during a tough time, talk with your parent(s) or a school counselor, who might be able to help link you up with a doctor, who will help you. 

-Denny Pintello

are they going to legalize marijuana

-jackh8, New York
Hey, Jackh8, that's a very complicated question you're asking. Drug laws in the United States--like most laws in our country--can come from different places. There are local, state, and federal laws, and sometimes they're in conflict with each other. Some places--Washington State and Colorado--have made recreational marijuana legal, even though it's still illegal under federal law. There are 20 states and the District of Columbia with medical marijuana laws on the books. Some of these laws were what we call ballot initiatives, where the citizens vote in an election for an issue, and some of them were passed by the state legislatures. Colorado's new marijuana law was passed by the legislature, while Washington's was a ballot initiative.
But the only way for marijuana to become legal in the entire United States is for the US Congress to pass legislation making it so. And they don't currently have any plans to do that.
-Marsha Lopez

Are you guys biased against weed?

-Swankdaddy, California

Maybe--but that's because we understand its harms--especially for young people.

-Susan Weiss

alcohol shouldnt be illegal for highschoolers considering many people do it anyway. why is this?

-skylerisdope, New York
You bring up an interesting problem. The US created the 1984 law raising the minimum legal drinking age to 21 because too many young people were getting hurt by drinking alcohol. Raising it to 21 helped to significantly reduce the number of young people killed in alcohol-related car crashes. By contrast, kids drink more heavily in places like Europe and Australia, where the drinking age is lower than 21.So, raising the drinking age was a good thing. And while too many kids in high school drink, many do not. Avoiding alcohol will help keep you safe. You can learn more about avoiding the peer pressure to drink at:
-Aaron White