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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Which drug is the most addictive and what makes it so addictive

-Little nicholas, Maryland

Hello Little n! This is an important question. There is a lot we still don't know about who becomes addicted, why they become addicted, and after how much drug exposure they become addicted. We do know that each person is different and each drug can affect each person differently. It's a little like playing “Russian Roulette” to pick which drug is most addictive. All drugs can result in addiction and any drug can be dangerous. There are many things that influence whether a person will become addicted. We know that the younger someone is when they start to use drugs or alcohol, the more likely they are to become addicted. If you use before your brain is fully developed (in your mid 20's) your risk for addiction is MUCH higher!

-Katia Howlett

Which drugs are consumed by teenegars the most?

-2400792, Illinois

Our most recent survey showed a huge increase in teen vaping between 2017 and 2018. The other most commonly used drugs are alcohol and marijuana. For more information, see:

-Emily Einstein

Which is more addictive or that your more likely to become dependent upon, alcohal or heroine?

-ben, Illinois

Hi Ben,
Dependence is common with both, so it mostly depends on what a person take.

-Dave Thomas

which is strongest ecstasy or cocaine

-Jayden-fvsufh, Georgia

Jayden, Exctasy and cocaine both have a powerful impact on the brain and with repeated use can lead to changes in the brain. More information about drugs and how they affect the brain can be found at:

-Redonna Chandler

Which is strongest ecstasy or cocaine

-coryfvsu4h, Georgia

Interesting question -- They are both strong, in different ways. Cocaine is a stimulant and can give you excess energy -- until, of course, it wears off, and then you "crash" and don't feel strong at all. MDMA can make you feel happy, but it has several dangerous side effects. Both drugs can lead to death. See information on different drugs here:

-Meyer Glantz

Which is the better way to leave marihuana?


Great question, BTR0077! Stopping marijuana use would be a great step toward a more positive future! Your brain isn't mature until your mid-twenties, so using any drug or alcohol can be harmful. Check out our Marijuana: Facts for Teens booklet: The booklet also contains the phone number and website of a treatment finder for U.S. providers. Congrats for taking the first step, which is deciding to quit!

-Emily Jones

Which is the country where more teenagers consume marijuana?


Hi pip
Thanks for the great question. We don't have reliable data for all the countries, and it's even more difficult to get data on just teenagers. But some of the countries with the highest MJ use among 15 and older include Iceland, the US, Canada, Australia, New Zeland, Nigeria, Spain and France.
Hope this satisfies your curiosity.
best of luck

-Ruben Baler

which is the difference between cigarettes and cigars and which of them harms more?


Hi BTR0077 - Both cigarettes and cigars burn tobacco, and the smoke is inhaled. Even though some people who smoke cigars say they are safer because the smoke only goes into their mouths and is not inhaled to their lungs, the smoke from cigars is just as harmful as cigarette smoke. The thousands of chemicals from cigarette or cigar smoke are absorbed into the body and can cause nicotine addiction, lung disease, heart disease, or have other harmful effects throughout the body. For more info:

-Kevin Walton

which is the drug that causes more deaths in a year?


Great question! The most deaths each year are caused by tobacco, over 480,000 each year! Check out the NIDA website for numbers and rates of overdose deaths caused by other drugs---deaths related to opioid overdose have increased dramatically!

-Aria Crump

Which is worse for you, heroin or cocaine

-Meemee, Oregon

Hi Meemee. This depends on what you mean by worse! Taking drugs, like heroin or cocaine, or misusing prescription drugs, has the potential to cause overdose and death even the first time you use them. They can also result in a substance use disorder. Any drug you use can be dangerous for you. Please protect your brain and your health—you need them! Check out the overdose death statistics for various drugs:

-Shwe Gyaw

which is worse juul or alcohol?

-babyjackjack, Illinois

hi BJJ
nicotine and alcohol are both very bad for the developing brain.
be smart and use to superpower to make good decisions.

-Tisha Wiley

Which one is more addictive weed or vape?

-AC, Illinois

Thanks for your question, Austin. That's a tough one to answer in part because vaping can mean different things. Vaping devices can be used to consume nicotine, THC (marijuana), flavoring or other subtances. Some companies falsely claim that vaping use is safe, but don't be fooled. Most vape manufacturers don't even know what chemicals are in their vaping devices, so folks using the devices really don't know what they are injesting. Now....regarding marijuana and tobacco...both are addictive, and use of both (especially when you are young) can put you at higher risk of using other drugs and at an increased risk of addiction in the future. The safest course of action is not to start using either substance and to quit if you do. Enough from me, learn about marijuana, nicotine/tobacco & use of e-cigarettes here:

-Marsha Lopez

Which one is safer vaping or smoking? Why?

-andrea, Maryland

Hey there - Smoking is definitely very harmful. There is no safe level of exposure to tobacco smoke. The long term effects of vaping are just not known. Most e-cigs used by vapers have the same nicotine that is found in cigarettes. Nicotine is a very addictive drug. Teens are especially sensitive to nicotine, so using e-cigs could lead to long-term addiction of nicotine just like what happens with cigarettes. There are a lot of chemicals in e-cigs in addition to nicotine, such as propylene glycol, glycerol, and flavor chemicals. Some of these chemicals are known to be harmful, and the safety of the others are not known. While e-cigs may be useful to help cigarette smokers stop smoking, they should not be used by anyone who doesn't smoke -- especially by teens, whose brains are still developing. Check out this link for more info:

-Kevin Walton

Which state in the USA drinks the most?

-Jim, Maryland

NIAAA surveillance data indicate that people in New Hampshire drink the most. Followed by Delaware and Nevada.

-Vani Pariyadath

Which vaping device is the worst for you? (JUUL, Suorin, Phix)

-samiw, Illinois

These devices all use liquids that may contain nicotine and flavorings, propylene glycol, glycerin, and more. The liquids are heated into an aerosol that users inhale. These products are marketed under all kinds of names but none are safe for youth to use.

-Suzanne Lim

why do people get hungry when they smoke weed?

-TY, New Mexico

The actual mechanism is not all that well known and there have been some rather paradoxical observations, but the effect (the munchies) has something to do with the actions of THC (marijuana's active ingredient) on a region of the brain called the hypothalamus, especially with a type of cells there called POMC neurons, which play an important role in controling feeding behaviors.
thanks for a great question.

-Ruben Baler

Why do people get prescribed medical marijuana? It must not be that bad for you then.

-CH, California

Hi Claire -- Thanks for the question. It's true that many states have approved marijuana for some medical uses, despite the fact that the Food and Drug Administration (FDA) has not approved it for any use. It's worth noting that two components of marijuana (THC and CBD) have been approved by the FDA for limitied uses. The States that have approved it for medical uses have not used rigorous evaluations to determine its medical value yet, and it remains to be seen if clinical research will prove its value.

-Ruben Baler

Why do people get so addicted to drugs?

-KateCross, California

Hi KateCross. Thanks for your question! There are many ways that drugs may lead to addiction. Drugs directly activate brain reward systems which makes you want to take the drug again. Those same brain systems also facillitate the development of habits, which again, make it increasingly likely you will take drugs again. Drugs also impair brain systems involved in assesing risk and adverse consequences associated with taking drugs (like being caught). On another level drugs can provide relief from social anxiety or stress, and you can come to rely on taking drugs to cope with those conditions.

-Steve Grant

Why do people get so addicted to smoking cigarettes?

-Wiley Wildcat, Illinois

Hey there Wiley Wildcat. The most addictive chemical in cigarettes is nicotine. Cigarette smoking causes nicotine to get to the brain quickly, within 10 seconds of inhalation. However, the rapid effects of nicotine go away quickly, like the feelings of reward, which causes the smoker to continue smoking to maintain the drug's pleasurable effects and prevent withdrawal. For more information on nicotine, check out NIDA's website - and

-Kevin Walton

why do people juul in my school bathroom?

-dino , Illinois

Hi dino.
Well, very good question. Very unfortunate that this is happening. Vaping is on the rise among your age group. Nearly two in five 12th graders report past-year use of some kind of vaping device. This raises concerns about the impact on brain health and potential for addiction. What they put in the device ranges from nicotine, to marijuana or hash oil, to “just flavoring.” When asked what they thought they were vaping in the past year, more than 25 percent of 12th grade vapers said “just flavoring,” 30 percent said “nicotine,” and 13 percent said “marijuana” or “hash oil". The resources below may also give you further insight:

Monitoring the Future Survey shows an alarming rise in teen vaping:

-Jacqueline Lloyd

why do people juul in the bathroom

-mrs piggy, Illinois

I assume because they are trying to hide the fact that they are doing it.

-Tisha Wiley

why do people like drugs? do they just do it to impress people?

-skyler1220, 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 in your teens. There is a lot of information about the health effects of drugs on NIDA's teen site here: Stay safe!

-Carlos Blanco

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