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.

Download Full Year

Why does my dad drink so much?

-TB, Illinois

This is a hard question to answer in a format like this. We recommend talking to another adult who you trust about this. A resource like would be useful to help people you trust discuss your dad's drinking.

-Aaron White

why does snorting cocaine hurt my nose so much

-JQ, Montana

Not only will snorting cocaine hurt your nose, but it will also cause nosebleeds and eventually ulceration in your nose and sinuses. The ulcerations can be so bad that you can end up with a hole in the middle part of your nose. The reason is that cocaine is usually made as either a hydrochloride salt or a free base. When you snort cocaine hydrochloride, it dissolves into hydrochloric acid which causes severe burns. As the free base, cocaine is highly alkaline (like lye or drain cleaner) and that leads to tissue damage as well. Cocaine itself will act as a local anesthetic and numb the tissue, so you end up not realizing how much damage you are doing to yourself.

-Marsha Lopez

why does the body take time to get rid of the alcohol

-Elijah, Maryland

Hi Elijah,
Alcohol is metabolized or broken down by the liver by specific enzymes. The rate of this metabolism depends on the capacity of these enzymes, which is about one standard drink per hour. If larger amounts of alcohol are consumed, the capacity of these liver enzymes is exceeded, which can result in a rapid accumulation of alcohol leading to overdose and serious consequences.
Check out this fact sheet on Alcohol Overdose for more information.
Hope this helps!
- Vijay

-Vijay Ramchandani

why does the U.S. have a higher legal drinking age than other countries?

-anonymous, Illinois

Because data generated by scientists during the Reagan administration determined that alcohol contributed to 50% of traffic fatalities and that raising the drinking age would substantially reduce traffic fatalities, which it did after President Reagan signed the law. There has been a straightline decrease in alcohol related traffic fatalities since then. See this fact sheet for more info.

-George Koob

why does uzi say that "xannys take the pain away"

-sssssssssssssss, Illinois

Drugs can make you forget or not care about pain--for a little while, but the pain comes back unless you find a way to actually deal with it.

-Roger Sorensen

Why does your body metabolizes ethanol to glucose?

-Memo Hérdez,

Alcohol is metabolized in the liver by specific enzymes that convert it to acetic acid, not glucose. Acetic acid can enter the energy cycle (called the citric acid cycle) in the body and generate calories. However, alcohol is not a good source of calories, and many people with alcohol problems develop malnutrition and other metaboiic conditions.

-Vijay Ramchandani

Why do some doctors want to prescribe their patients with something that is not meant for them?

-Kylie-FVSU4h, Georgia

They are prescription drugs for a reason. A clinician can help understand how to use such drugs and how not to use them. If used as directed and prescribed, they can help people some with moderate to severe pain. However, if misused, they can be VERY dangerous.

-Dave Thomas

why do some medicines have a great side effect

-coryfvsu4h, Georgia

If by "have a great side effect", you mean "produce a high", scientists are still trying to understand why some drugs can be addictive. Different addictive drugs act on the brain in different ways, but they all cause the release of the neurotransmitter dopamine in the brain's reward area, which is what causes the pleasurable sensation (the high). You can learn more about dopamine here.

-Vani Pariyadath

Why do some people become addicted to drugs while others don't?

-Dre507943, Illinois

Hi Dre507943! Great question! There is a lot of variation in who becomes addicted to drugs, and a lot depends on your own family's genetic susceptiblity to substance abuse and the environment you grow up in. The best bet is to not even start taking them and avoid the risk! See these easy-to-understand videos on how anyone can become addicted, and why drugs are so hard to quit:

-Mary Kautz

why do some people become addicted while others don't?

-DE, Montana

Hello d.edmisten,
This is a great question, and I can only give you a partial answer. We know that genetics are a factor, a family history of addiction is one of the biggest risk factors for people. We know that people from backgrounds where they have experienced trauma and stress are also at greater risk for addiction. Factors such has higher socioeconomic status, years of education, healthy lifestyle, are factors that protect people from becoming addicted. We are learning a lot about the biology of addiction and this is increasing revealing the mechanisms underlying risk and resilience. For more information, check out these videos and this link

-Jinhee Lee

Why do some people become addicted, while others don't?


Hi Cacho -- This is a complicated question. We cannot predict how many times a person must use a drug to develop an addiction; it's different for different people. We do know that people who have a family history of drug use are more likely to develop an addiction. But environment is also important and can "balance out" the risk from family hsitory. Learn more here:

-Anto Bonci

Why do some people get addicted and some do not?

-ser, Maryland

No one factor can predict if a person will become addicted to drugs. A combination of factors influences risk for addiction. The more risk factors a person has, the greater the chance that taking drugs can lead to addiction. For example:

  • Biology - The genes that people are born with account for about half of a person's risk for addiction. Gender, ethnicity, and other mental disorders may also influence risk.
  • Environment - A person's environment includes factors such as peer pressure, physical and sexual abuse, early exposure to drugs, stress, and parental guidance can greatly affect a person's risk.
  • Development - Although taking drugs at any age can lead to addiction, the earlier that drug use begins, the more likely it will progress to addiction. This is particularly problematic for teens. Because areas in their brains that control decision-making, judgment, and self-control are still developing into the 20's.
-Jinhee Lee

Why do some people get addicted to drugs while others don't?

-MA, Illinois

Hi MA -- It is difficult to determine why some people get addicted and others don't. Experts think it's about 50% genetics (what you inherit from your parents and grandparents) and 50% environmental (who you hang out with, how well you thrive during childhood etc.). Check out this video to learn more:

-Meyer Glantz

why do some people get more/faster addicted while others it takes time ?

-joy is happy, Illinois

Great question Joy is happy! Scientists believe that drug addiction results from the interaction between a person's genes and the enviornment. It's your genes that make you different from your friends. It's also the genes that increase the risk of some people liking drugs and becoming addicted to drugs whereas other people may not even want to try a drug. Not all poeple who try drugs will become addicted. But depending on your genes, you may have an increased risk of developing addicitive behavior if you choose to try drugs.

-Roger Sorensen

Why do some states make some drug legal

-PS, Illinois

Thanks for the question (and it's a good one!). Legalization of marijuana for adult recreational use and for medicinal purposes is currently the subject of much public debate. For the last few years, the Department of Justice has said that won't focus on enforcing Federal marijuana laws when state laws allow for possession of small amounts of marijuana and would give states the flexibility to test new policies for both ‘medical' and recreational use of marijuana. Whatever happens, public health experts are worried that these changing policies could lead to more use among teens. Regular marijuana use as a teen may harm the developing brain – making learning and memory worse – and can impair the ability to drive safely (especially when combined with alcohol).

-Marsha Lopez

Why do teen like drugs

-Znovo, California

See these videos on how anyone can become addicted, and why drugs are so hard to quit:

-Ruben Baler

why do people think it is cool to do drugs

-LA, New Hampshire

I am not sure i can give you a scientific answer to your question. I can speculate though that sometimes young people tend to follow their peers, and something that is objectively bad for you becomes popular. Young people sometimes tend to take risks and feel a strong urge to belong. That combination sometimes makes us do stupid things and call something cool just to fit in, even if we know deep down that it's not.

Hope this is helpful.

-Aaron White

Why do people think vaping is cool? It makes you look like an idiot.

-Garfield , Illinois

Hello! Thank you for participating in Chat Day! This is a good question. The Monitoring the Future Survey shows an alarming rise in teen vaping:

Information about vaping can be found here: Drug Facts – Electronic Cigarettes (E-cigarettes):

It is unclear why people think it is cool - it could have to do with a number of reasons like people wanting to fit in, peer pressure, advertising, etc. This website about peer pressure could be useful to some of the people you are seeing!
Check out

-Kristen Huntley

why do people try to peer presser someone into drug use

-JL, New Hampshire

Hi JL. People are social beings. We tend to want to do things with others and may build bonds around things we do together. The most important thing is trying to stay true to yourself and feel comforatble with who you are. It may seem sometimes that your friends' opinions matter more than your own opinions about yourself -- but THAT IS JUST NOT SO!

-Aria Crump

Why do people turn to drugs in the first place

-Foxtrot15, Illinois

People do drugs for lots of different reasons. Some people do it to impress people. Some people do it feel good in the moment, kind of like eating junk food. But the effect of using drugs - any drugs - on your brain and body can be severe, especially if you start using drugs when you are a kid or in your teens. There is a lot of information about the health effects of drugs on NIDA's teen site here:

-Tisha Wiley

Why do people use drugs even though they know they are bad for them?

-ER, Oregon

Hi there. Great question.
People use drugs for a number of reasons--including availability, the people around them may use, they think it is cool, they are experiencing physical or emotional pain, etc. Most people may not be fully aware of the harmful and addictive effects of drugs. It is important for teens to be informed and know the facts about drugs. You can learn all about the impacts of different drugs on the body here:

-Jacqueline Lloyd

Why do people want to do drugs?

-wms, Illinois

Thanks for the question, wms! There are lots of reasons people may want to use drugs or start to use drugs, such as peer pressure, boredom, curiosity, and so on. People can know drugs are bad for them, but they may still choose to take the risk, while others may not be aware of all the risks. It is important to know the risk of drug use, and think ahead about how to resist drugs if they are offered. Here are some resources about the health effects of drugs and about peer pressure.
You can read more about health effects of drugs on NIDA's teen site here:

-Belinda Sims

Why do people make drugs and expect people not to get addicted? (prescription opioids)

-klaroque, Wisconsin

Hi klaroque,
They are prescription drugs for a reason. A clinician can help understand how to use such drugs and how not to use them. If used as directed and prescribed, they can help people some with moderate to severe pain. However, if misused, they can be VERY dangerous. It is also important to keep in mind that in past years, some clinicians have inappropriately prescribed or have prescribed too much, was has also contributed to our opioid crisis. Educating doctors has improved this overprescribing practice as of late and we hope we will continue to see improvements.

-Suzanne Lim

why do people overdose on drugs?

-guinea pig!, Oregon

Hi guinea pig! Your question makes me think that you have heard a lot about people overdosing when using opiates such as heroin. Opiates are used to treat certain kinds of pain. However when people take too much, it can cause the person to stop breathing and they can die. People can take too much opiates the first time they use them but more people overdose when they regularly abuse the drug. These people can overdose on drugs because they become tolerant to the effects of drugs. When they become tolerant, they need to take more of the drug to get the same feeling. By taking larger amounts of a drug, the person risks overdosing on the drug, and the harmful consequences of using too much drug.

-Roger Little

why do people overdose?

-guinea pig!, Oregon

Hi and thanks for the question. Most overdoses are accidental. Some people who use drugs to try and get high don't know how much of the drug they're actually taking. Others are trying to get as high as possible, and the amount needed to kill a person is often not much more that the amount needed to get high. It's is also true that some overdoses are intentional, that is, done to commit suicide. Read more about overdoses here:

-Dave Thomas

why do people prefer vaping

-saroo, Illinois

Hi saroo, People may prefer vaping for different reasons. It could be because they think that they are easily available or because they think that vaping is safer than cigarettes, but we don't have data on the long-term health effects. For more information on vaping, check out our Teen Website.

-Aria Crump

Why do people put drugs in kid's food and candy? Just why?

-DJ, New Hampshire

Hi! Your first question is an excellent question, and your second question is even more awesome.
Given the harmful effects of drugs on the developing brains of children and teens, as well as the fact that drug use can lead to misuse, this is very concerning. Our goal is educate teens and adults on the harm of drugs, and prevent this sort of thing from happening.

-Jacqueline Lloyd

Why do people say it feels good/ what about it feels good to be high or drunk?

-DBRAD, California

They are referring to the temporary often pleasurable effects of addictive drugs. Once that fleeting feeling goes away, though, the person falls into a vicious cycle in which he/she eventually uses to just feel normal. Its a really bad deal in the long run.

-Aaron White

why do people smoke in general?

-her508310, Illinois

Hi her508310,
Cigarettes contain nicotine, a highly addictive chemical found in tobacco products. Many teens underestimate how easy it is to become addicted to nicotine. Addiction can make quitting harder than it seems; it keeps people smoking even when they want to quit. Because of nicotine addiction, 3 out of 4 teens end up smoking into adulthood, even if they plan to quit after a few years.

-Suzanne Lim

why do people start drugs if they know they are not going to be able to stop?

-queen.bee, Illinois

Hi there queen.bee.
People can start using drugs for a number of reasons--including availability, the people around them may use, they think it is cool, they are experiencing physical or emotional pain, etc. The thing is that most people may not be aware of the effects of drugs on the brain, and that drugs can be addictive. It is important for teens to be informed and know the facts about drugs. For information on the effect of drugs on the teen brain, please look at the following resources:
Publication: The Teen Brain: 6 Things to Know

-Jacqueline Lloyd