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

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.
-Aaron White

Also what about mariquana with hi cbd and low thc content.

-xmen515, Maryland
Hi again xmen515,
You're asking good questions today--bravo!
Yes, some parents are giving hi-CBD (cannabidiol) marijuana to their children with a terrible form of epilepsy called Dravet Syndrome. CBD is another cannabinoid chemical related to THC but doesn't produce a high and has probably a lot of beneficial health effects. But the best way to deliver CBD to Dravet patients and others would be through actual medications made from CBD, with none of the other harmful chemicals in marijuana. A CBD drug is already being tested in children with Dravet Syndrome, and if it works, there will be no need to breed marijuana strains or give children marijuana to treat their disease.
-Eric Wargo

Am i secondhand smoking is I can smell the smoke?

-jdizzle813, Maryland

If u can smell the smoke its likely that some nicotine will get into your brain but the questions is how much.  Just smelling smoke when u come close to someone who is a smoker is unlikely to deliver much nicotine into your brain but if you are in a room where people are smoking and stay there for several minutes then you will get sufficient nicotine into your brain to affect it.    

-Nora Volkow

apparently recent studies have shown that the most dangerous drug is alcohol... is that true?

-lalala, New York

You are right that some studies suggest that alcohol is more dangerous than many, if not most, other drugs. However, it really depends on how you define "dangerous". In terms of the number of years of life lost due to drugs, the number of deaths due to drug overdoses, the number of fatalities caused by injuries sustained while under the influence of drugs, alcohol ranks #1. But part of the reason is because there are so many people in the world who drink alcohol. Way more people drink alcohol than do other drugs. This makes it hard to compare the consequences of various drugs. 

-Aaron White

are 'soft' drugs less harmful than 'hard' drugs?

-lalala, New York

Not exactly sure which drugs you are considering soft vs. hard.  Some drugs are definitely more addictive than others (e.g., methamphetamine) and  people can be more sensitive to some drugs than others because of their genetics.  Alcohol and tobacco are among the most damaging--because they are so widely used--are they hard or soft?

-Susan Weiss

are alcohol and smoking bad combinations?

-devondonahue, New York

Both alcohol and nicotine can produce nausea and some people get really sick from the combination. If you meant smoking marijuana, both can impair balance, coordination, reaction times, decision making and attention, making the odds of being injured or making back choices higher if you combine the two drugs. 

-Aaron White

are all drugs addicting

-whiteman03, Maryland

Yes, most drugs of abuse can be addicting.  Research shows that brain development continues well into a person’s twenties. Alcohol and drugs can affect this development, and contribute to a wide range of problems. There is a lot of information about the health effects of drugs on NIDA’s teen site here:

And try this brand new “e-poster”---“Drugs and the Body: It Isn’t Pretty”

-Joe Frascella

Are all drugs fatal or cause damage to your body if used on a daily basis?

-Soto2016, Texas
Depends on the drugs and the doses used.
For example, one glass of wine a day in an adult would not be fatal but 5 glasses a day will be harmful and even higher alcohol intake can result in death from overdose, accidents or liver damage.  
-Nora Volkow

are any drugs good for you

-drugs, New York

Hey drugs.  Is this a trick question?  It's a good one.  There are drugs that can be good for you--they are the ones that your physician prescribes.  Your physician knows which drugs at what dose will help you with an illness or health condition.  They are usually safe for you when used properly!  But used improperly, they can become very dangerous.  You might take a peek at this Prescription Drugs Fact page for more info:

-Joni Rutter

are bath salts the same as bath salts? what are bath salts, they sound like inhalants

-AG, New York

HI AG - good question.  And the answer is no.  There are bath salts that are meant to be used in an actual bath, and these tend to be things that smell nice or make your skin smooth.  There are also 'bath salts' that are drugs meant to be taken by mouth and not used in baths at all.  The 'bath salts' term is just used to get around the illegality of selling these substances for human consumption.  It is important to know and remember that these 'bath salts' are very different from each other and that they can contain any of a number of chemicals, many of which we do not know much about.  For more information check out

-Steve Gust

are celebrities allowed to have drugs?

-Blackgurl, Maryland


-Jack Stein

Are certain drugs better for you than others?

-Lemons1018, Pennsylvania

None of the drugs are better for you, but its rather that some are worse for you than others. Which drugs are worse depends on your genteic vulnerability.

-Nora Volkow

Are dissociation drugs are the worst or harder drugs like crack? - Rory

-Aveson, California
Hi Rory,
Good question, and it's a hard one to answer. Comparing different types of drugs is like comparing apples and oranges--they have different effects, and different people react differently to the same drug. Dissociatives cause more perceptual effects (distorted perceptions and feelings) while crack might be more energizing, but it's hard to say which is worse.
Check out our fact sheets on these drugs:
-Eric Wargo

Are drugs bad for animals?

-HappyCows42, Massachusetts
Hi again HappyCows42.  Drugs can definitely affect animals.  In fact, a lot of the research we support uses animals to examine the effects of drugs because animal brains are a good model for human brains.

You should also check out this great blog by our very own Dr. Joe Frascella on drugs being "discovered" first by animals!

-Joni Rutter

Are drugs bad for you?

-Azreal Garcia, California
Hey Azreal,
Good question.  Drugs include illegal drugs, like heroin or cocaine as well as drugs that a doctor might prescribe for you.  Abusing any drug is bad for you but using a drug that your doctor has prescribed in the way it was prescribed can be very good for you.  Those drugs are called "medicine".    
-Dave Thomas

Are drugs good for you?

-JcPuebla, Texas
Hey JC! The term "drugs" is so broad that it's impossible to give a simple yes-or-no answer to your question.
Usually when we think of "drugs" we think of illegal substances like heroin, cocaine, etc.  These "street drugs" have no known medicinal benefits and that's why they're illegal.  But the term "drugs" also includes prescription medications.  Prescription meds do have benefit and are safe (they're approved by the FDA to be sure) -- but they're only safe if used EXACTLY as prescribed, by the person to whom they are prescribed, for the reason they're prescribed.
The same is true with over-the-counter meds (like cold medicine or cough syrup) that you can get in a drugstore. Virtually any prescription or over-the-counter drug can be misused or abused, and in that case they're definitely not good for you.  Thanks for your question!
-Lori Ducharme

are drugs like viruses and attack cells

-ra, New York
Dear ra, that is a great analogy. Drugs do act like viruses that impact the brain in a very significant way. Drugs have strong behavioral, chemical and emotional effects of drugs. For example, drugs contain chemicals that take over the communication system in the brain, and therefore, interrupts the way in which nerve cells send, receive and process this information. Drugs, in other words, imitates the brain's natural chemical signals, and also intensifies the 'reward' circuit of the brain. Drug addiction actually changes the brain and compulsive drug seeking is part of it, this is why addiction is such a devastating disease. 
Stay healthy! 
-Will Aklin

Are E-Cigarettes safer to use than normal cigarettes, and if they are, why?

-kmussett, Pennsylvania

Hey Kmussett,  Great hearing from a middle school student.  Electronic cigarettes are new to the scene and we don't have a lot of scientific data on their safety or effects yet.  While they may be advertised as "safer" than cigarettes, there is a lot we don't know about the health consequences of e-cigarettes.  There have been a few reports of e-cigarettes exploding when people use them causing some serious injuries to their hands and faces. The bottom don't know what you are getting in these products or their health consequences. Best to wait until we get more information---and it could take a few years before we see good research studies on e-cigs.  For more information see:

-Cindy Miner

Are E-cigs a safe alternative to cigarettes? I've been told they are but I don't know.

-5w1m5w4g420, New York
Is your name a chemical formula or something???   
We are not sure of the safety of E-cigs at this point. But a lot of people are starting to use them.  We are just starting to do research on their safety, and we may look at if they can be used to help people stop smoking real cigarettes.  
-Dave Thomas

are electronic cerets worse then real cigars

-Allen12, Maryland
Hi Allen12,
Good question! We actually don't know the answer to this yet. E-cigs don't have the cancer-causing tar that cigarettes and cigars have, but they do have other possibly harmful chemicals, and they still have nicotine, which is very addictive. Scientists are studying this, and hopefully we'll know more soon!
-Eric Wargo

are electronic cigarettes a safe alternative to smoking

-jd, New York
Hey JD,
Great question.  E-cigarettes are an unregulated product, so there aren't a lot of studies out there on what's even in them, much less whether they are safe (or safer to use), or if they are effective as a smoking cessation product.  Many people think there are less toxic or cancer-causing chemicals in e-cigs.  In some instances that may be true, but in others, it is fact, some e-cigs contain even more cancer-causing chemicals than a regular tobacco cigarette.  One thing is for sure, a lot of people are starting to use the, so the research is going to have to catch up!  If you want more information of them, check out:
-Dave Thomas

are electronic cigarettes still bad for you?

-ashlin5702, Maryland
Good question, ashlin5702!  
Although they do not produce tobacco smoke, e-cigarettes still contain nicotine and other potentially harmful chemicals. Nicotine is a highly addictive drug, and recent research suggests nicotine exposure may also prime the brain to become addicted to other substances. Also, testing of some e-cigarette products found the vapor to contain known carcinogens and toxic chemicals (such as diethylene glycol and nitrosamines), as well as potentially toxic metal nanoparticles from the vaporizing mechanism. The health consequences of repeated exposure to these chemicals are not yet clear.
Stay tuned for when more research comes in to address this very question! Learn more about electronic cigarettes at -
-Joni Rutter

Are hookah pens without nicotine bad for you?

-big bird yellow, New York
Ahhhh, good question big yellow bird (are you the real Big Bird?)
You are talking about electronic cigarettes, and they are becoming quite popular.   They may not be dangerous at all if nicotine or other drugs are not put in them.  However, we are not positive at this point. They just started becoming popular and there is not much research on safety.  We are starting work on that, and will hopefully have your answer soon....
-Dave Thomas

Are hookah's bad for you?

-kittykat406, New York

Hi Kittykat, Thanks for asking this question. There is a common misconception that smoking hookah isn't bad for you, but it is really just another way of smoking tobacco and we all know that is bad for you. They might add some fancy flavors and tell you that the water is filtering out the bad stuff. Don't believe them -- you are still inhaling tobacco smoke and exposing yourself and your lungs to nasty stuff. There are no safe tobacco products -- don't believe the hype out there. Hookahs still deliver the addictive drug nicotine, and research suggests that smoking hookah is associated with all sorts of the same health problems associated with smoking cigarettes, such as cancers, respiratory illnesses, and addiction. In fact, early results of current research being conducted suggests that one session of hookah smoking is like smoking multiple cigarettes!

-Jeff Schulden