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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Can cigarettes affect your eyesight?

-iloveny210, New York
Great question! Short answer: yes. Long answer - health consequences causally related to smoking include blindness, cataracts, and age-related macular degeneration. Check out the summary of the just released Surgeon General's report on tobacco for more information on these and other health consequences.
-Cindy Miner

can a person die from mariijuana?

-$QuAd98, Maryland

Hey $quad!  Good question.  Marijuana can lead to tragic outcomes, but perhaps not in the way you're thinking about.  Marijuana affects judgment and decision making, so using it can cause you to do things you might not do when you're thinking straight -- like engaging in risky sexual behavior, which can expose you to HIV and other diseases, or getting in a car with someone who has been drinking, or trying to drive your own car yourself while high. All of those situations could end pretty badly, right?  As for a straight-up answer to your question, it's hard to know how marijuana will affect a specific person at any given time, because its effects vary based on individual factors -- a person's genetics, whether they've used marijuana or any other drugs before, and how much marijuana they consume.  And the effects can be even more unpredictable when marijuana is used in combination with other drugs.  Thanks for your question!

-Lori Ducharme

Can addictions to drugs be genetic?

-Kim Jong Un, New York

Most definitely! In fact, genetics plays a very significant role in determining if a person will ultimately develop a drug problem. However, other factors contribute as well, including one's environment in which they grow up and peer influences. 

-Jack Stein

Can alcohol cause cancer when drinking to much

-laylay11, California

Yes, for sure. Drinking a lot of alcohol over time increases your chances of developing cancers of the head, neck, mouth, throat, and breast. You can learn more about these risks at:

-Aaron White

can alcohol destroy your body?

-faithchim, Maryland
Yes, alcohol can do lots of damage to the body.
As you drink more and you have more alcohol in your bloodstream, you can experience impaired judgment and difficulty making good choices. You may also have difficulty controlling urges, making it more likely that you will do something dangerous. You can also experience impaired memory -- waking up the next day and not being able to remember what you did while you were drinking.
Still more alcohol can cause potentially fatal side effects, including difficulty breathing, low heart rate, and loss of consciousness.


Drinking too much can also cause some cancers. It causes many kinds of stomach problems. It causes the liver to swell up and develop lots of scar tissue. It also interferes with the immune system and can make it harder for the body to fight off infections. It also damages the brain and interferes with how the brain grows and develops. You can learn more about these effects at
-Aaron White

can alcohol kill you

-tate, New York

Absolutely! Too much alcohol from any source -- beer, wine, liquor, -- can shut down the parts of the brain that keep us alive, leading to death. 

If you drink enough alcohol, parts of the brain that are important for keeping us alive can shut down. Then, the heart can stop beating and we can stop breathing. In essence, it's like alcohol flips a switch and shuts the body off. This is what's known as "alcohol poisoning."

It is also important to point out that having any alcohol at all can increase the chances of dying from injuries, such as falls, drownings, or car crashes.

Drinking heavily over a long period of time can contribute to problems with your liver, pancreas, and heart, can impact your immune system, and can increase your risk for certain types of cancer. For more information on how alcohol can impact your health, check out:
To learn more about how alcohol can affect kids, how to learn to say NO to kids who offer it to you, check out:
-Aaron White

Can alcohol worsen a teens depression?

-Faith Watkins, Texas

hi Faith.  Good question, and one that we hear a lot. The short answer is yes.  But the relationship between alcohol and depression is complicated.  Some people turn to alcohol when they are depressed. The problem is, alcohol isn't a good way to cope with problems, and it is a depressant drug that can make things worse.  If you or a teen you know is feeling depressed or using alcohol, talk to a trusted adult (parent, relative, counselor) about connecting with some help to assess the problem and see if treatment might help.

-Joel Sherrill

Can coke knock off your nose completely if you do it for a while?

-yunglean, New Mexico
Well I don't know about that.  It would be upsetting!!!  Snorting cocaine can cause extensive damage to the nasal mucosa (the lining of you nasal passages), which is serious.  However, I do not think your nose will fall off.
-Dave Thomas

can crack eventually kill u

-weed machine, New York

Hello there, WM! Yes, it can. As you might know, crack (which is a form of cocaine) is a highly addictive drug. And even a single usage of cocaine can cause heart attack or stroke, which may result in sudden death. But that's not the only health effect to be concerned about. Cocaine can also cause headaches and gastrointestinal complications such as abdominal pain and nausea. Because cocaine tends to decrease appetite, chronic users can become malnourished as well. Snorting cocaine (inhaling through the nose), can lead to loss of the sense of smell; nosebleeds; problems with swallowing; hoarseness; a chronically runny nose; and damage to the nasal tissues. Cocaine abusers can also experience severe paranoia. If you are curious, check out this page:

-Anto Bonci

Can dangerous drugs be modified to become less harmful? What are some effects that vicodin can have on a person? Where do most of the illegal drugs in the United States come from? Could there ever be anyone immune to the effects of harmful drugs?

-eechero, Texas

Hi eechero - thanks for your questions.  Let me try to answer some of them at least.  Your question about modifying drugs to make them less harmful is an excellent question. There has been a lot of research effort to try to develop pain medications, for example, that are less addictive.  Some progress has been made but we have a long way to go.  Vicodin is an opiate drug that reduces pain but is also addictive for some.  If taken in high doses it can cause euphoria, disorientation, and such things as respiratory depression.  Illegal drugs come from many sources, some in the US (marijuana, methamphetamine) and some outside the US (heroin, cocaine, ecstasy).  Your last question is a very good one.  It is true that there are large differences between people in their responses to drugs.  Some people are a lot more susceptible to the euphoric effects and so are much more susceptible to becoming addicted.  However, since all drugs of abuse affect the most basic parts of our brain having to do with reinforcement and reward, it is doubtful that there would ever be total immunity to their effects.

-Steve Gust

Can diseases be inherited ?

-officivl_tjc__, New York

Hey officivl_tjc_--great question!  I'm a geneticist and we've worked very hard to address your question.  

It's true that you can inherit diseases from your parents.  For Huntington's Disease is caused by a genetic defect that, if passed on, causes a person's offspring (their child) to be affected. That means that Huntington's Disease is 100% genetic. Inheritance, in the form of genes, plays a large role in drug addiction also.
Research shows that drug addiction is about 50% heritable. BUT.....while genes play a big role, they are only part of the picture. Other factors, like having friends who don't use drugs, or being involved in sports and other recreational activities, also affect your risk of trying drugs and of becoming addicted to them. Researchers are trying to find the genes that make you vulnerable or resistant to addiction, in order to find ways to improve treatment and prevention approaches.
Want more information on genes, addiction and teens? Check out: and
Get accurate drug facts to make healthy decisions for your brain and body! 
-Joni Rutter

can snorting kool-aid cause brain damage

-aveson, California
Snorting Kool-Aid...really?!  I don't know that it will cause brain damage, but I know there is high likelihood that it will cause irritation to one's respiratory system! I wouldn't recommend it! 
-Joe Frascella

can some drugs that are considered bad be used for good like treatment in a hospital

-yayme32, Maryland

Yes--there are a number of drugs that have medicinal effects when used properly but can be very dangerous when abused.  The best example is opioids (vicodin, oxycontin), which can be very helpful for treating pain, but can also be very dangerous when not used as prescribed--in fact the number of overdose deaths due to opioid abuse was about 12,000 in 2010.  

-Susan Weiss

Can someone get addicted to an acoholic drink after their first try? even if it is the first time they have ever drank alcohol? is it likely to be zero intolerant to your first drink and get drunk very easily?

-asdfghjkl, Maryland

Researchers found that the earlier someone has their first drink of alcohol, usually meaning more than a few sips with family, the more likely they are to become an alcoholic. It isn't known whether a few sips is enough to make that happen or if more alcohol is needed. The best bet is to avoid alcohol completely until your brain is done developing in the early 20s. You can learn more about the effects of alcohol on kids at:

-Aaron White

Can steroids affect a girl's period?

-biancaP-p3, Texas

Hi biancaP-p3. Yes, steroids certainly can affect a girl's period. Many steroids are hormones or act like hormones in the body. This is just one way that these dangerous chemicals affect your body.  Thanks for your question!

-Marilyn Huestis

can steroids permanetly make you strong?

-bmorse, New York

no--those effects tend to go away when you stop taking them, but some of the harmful effects can be permanent--e.g., stunted growth, the masculinizing effects in females, such as deepened voice;  and feminizing effects in males.

-Susan Weiss

Can street drugs such as heroin and meth be used recreationally? or are they too addictive?

-SETLAX32, New York

There are people who use drugs occasionally and don't become addicted. In part that depends on their genes and their home/school life.  But that said, there are at least 2 problems with using drugs recreationally--one is that you never know what you are really getting, and whether it might be contaminated with poisonous ingredients.  The second is that some drugs (like heroin and meth) are more addictive than others--depending in part on how they are taken.  Smoking or injecting are among the most dangerous ways because the drugs get to the brain very quickly. And there are other diseases also linked to injecting drugs, such as Hepatitis and AIDS

-Susan Weiss

Can supplements affect growth?

-whiteshoes81, Maryland
Hi whiteshoes.   There is a lot of debate about whether dietary supplements do anything for you.  I have never heard of them making you grow, or stopping growth for that matter.  It's probably better to get everything you need from food! 
-Dave Thomas

Can taking a drug like cocaine or marijuna once potential kill you?

-GEFRE, New York
good question.  My answer is yes, but not necessarily for reasons you might think.  While there are documented cases of people dying from a single exposure to cocaine, there are other indirect ways these and other drugs can have tragic consequences even if you were to just use them once.  Think about it -- drugs impair your judgment, your memory, and how you process information.  If you were to drive a car, or get into a car with a drug-impaired driver, you're seriously increasing your risk of something awful happening.  So it's not just the drug you have to think about -- it's the whole context of the situation and the possible results.  Stay safe and take care!
-Lori Ducharme

Can the effects of drugs, like feeling dizzy or sick to your stomach, last even after you stop doing drugs?

-maryd@aslacadem, New Mexico
Thanks for your thoughtful question.  Most drugs have both short- and long-term harmful effects, although dizziness and nausea are often short-term. However, if the drug has some damaging effects to certain brain areas, long-term dizziness can result. 
You might want to check specific drugs in our teen Drug Facts section: 
-Joe Frascella

Can People Overdose Themselves With Different Type Of Drugs ?

-bill, California

Hi Bill.  This is a very important question.  In a word, yes people can overdose on just about any kind of drug, but some are more dangerous than others and can kill you even if you take them only once. Painkillers like oxycotin contain high amounts of a class of drugs called opioids, and one effect of these drugs is they reduce your breathing. If you take too much you simply stop breathing and die. Other drugs, like amphetamine and stimulants, can cause heart attacks. Even antibiotics can be dangerous; for example some people are allergic to penicillin. Even non-prescription drugs like Tylenol (acetaminophen) can cause very rare but potentially fatal skin disorders as well as liver damage. For more information on various drugs and what they can do to your body, see

-Steve Grant

Can pregnant women who smoke put the baby in any danger? If so, what kind of danger?

-GEFRE, New York
Yup, GEFRE, it can be a danger to the baby.  Pregnant women have to be real careful in what they consume or put in their body.  
We know now that babies born to smokers can be smaller than normal when they are born, and some studies show that these babies may have developmental problems and somewhat decreased cognitive abilities (shorter attention spans, inability to focus on a task) that may be related to maternal smoking. Our nicotine research report has a section on smoking and pregnancy at
-Dave Thomas

Can prescription drugs be as harmful as illegal drugs?

-bubbles7977, Maryland
Dear bubbles7977,
Yes, prescription drugs can be as harmful as illegal drugs.  Some prescription drugs are as addictive as illegal drugs if used the wrong way (i.e., not as prescribed).  Here is more information:

There is lots of information on NIDA’s Web site at

Check out the "Students and Young Adults" tab.

-Michelle Leff

Can psychotropic hallucinogens have effects of causing you to have irrational emotions?

-ryan_thorpe, New York

Hi, RT. Yes they do. Hallucinogens produce rapid, intense emotional swings. LSD, peyote, psilocybin, and PCP are drugs that cause hallucinations, which are profound distortions in a person’s perception of reality. Under the influence of hallucinogens, people may see images, hear sounds, and feel sensations that seem real but are not. LSD, peyote, and psilocybin cause their effects by initially disrupting the interaction of nerve cells and the neurotransmitter serotonin. For more info, please go to:  

-Anto Bonci

Can rehab help you get over an addiction to alcohol? How long will it usually take?

-Aveson, California
Absolutely! Rehab certainly can help a person deal with their addiction to alcohol. How long it takes depends on several things, including how serious the problem is and what kind of rehab the person goes to, whether in-patient or out-patient. Most people who treat alcoholism believe that alcoholism is a life-long condition and that a person never really gets over it but, rather, learns to cope with it. 

Here is a link to further information about the signs of alcoholism and suggestions for quitting:


-Aaron White

Can small amounts of alcohol on occasions eventually add up and cause permanent brain damage or memory loss?

-emily_ho, Pennsylvania
Hi Emily. Probably not, but they can produce other kinds of serious problem, such as alcohol addiction or DUI (driving under the influence), which is a major cause of injuries and death. Bottom line, be careful! 
-Anto Bonci

Can smoking help with stress and pain?

-Samniesha, Mississippi

if u are a smoker, smoking will decrease anxiety and might decrease pain; however when u stop smoking the anxiety will be worse and similarly the pain will be exacerbated, which is why smoking is not a good solution 

-Nora Volkow

Can smoking marijuana make you seem to have an all of a sudden hunger issue causing you to constantly eat?

-YOE23, Texas
Marijuana has the properties of an appetite stimulant, which causes an increase in appetite.
Check out the following site for more information on marijuana:
-Joe Frascella

Can smoking tobacco lead to cancer?

-Batman369, New York

Dear Batman...(You would NEVER see Batman smoking) Tobacco use is the leading cause of preventable illness and death in the United States. It causes many different cancers as well as chronic lung diseases, such as emphysema and bronchitis, and heart disease.

Lung cancer is the leading cause of cancer death among both men and women in the United States, and 90 percent of lung cancer deaths among men and approximately 80 percent of lung cancer deaths among women are due to smoking.

Smoking causes many other types of cancer, including cancers of the throat, mouth, nasal cavity, esophagus, stomach, pancreas, kidney, bladder, and cervix, and acute myeloid leukemia.

People who smoke are up to six times more likely to suffer a heart attack than nonsmokers, and the risk increases with the number of cigarettes smoked. Smoking also causes most cases of chronic lung disease.

-Cindy Miner

can smoking weed kill you?

-ilovepandas101, New York
Hi ilovepandas101
thanks for the question.
Not directly. but it can indirectly increase your chances of dying. in case you are curious, more here
hope this makes sense to you.
-Ruben Baler