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 marijuana change your feelings/attitude?

-yffjc, New York
Hey yffjc:  Thanks for your question!  It's a complicated question....individuals respond to drugs differently, so there's not a single answer.  In general, people take drugs for different reasons.   The bad thing is that those effects wear off and people become addicted because they have to keep taking the drug to keep the high.  Once that happens, other effects of the drugs take over and they "hijack" the brain so that you can no longer make good decisions.
Serotonin is clearly an important neurotransmitter in addiction and contributes to the intoxicating effects of alcohol--and also may be the link to alcohol and depression.  There is definitely a higher incidence of mental health issues in people who do drugs, but we don't have a good handle on why this is.  Maybe you will become a scientist and help us figure this one out!
You can check out this great webpage on the NIDA for teens site that explains what effect drugs have on the brain:
-Joni Rutter

Can marijuana cure cancer?

-ashley.bowling, Kentucky

There are no studies that have shown that marihuana can cure cancer.    However the value of cannabinoids (the active ingredients in marijuana) in cancer treatment is being evaluated by researchers.

-Nora Volkow

can marijuana intoxicate drivers and cause them to be unsafe on the road?

-sampugliese, New York
Hi sampugliese,
Great question! The answer is a definite yes. Marijuana more than doubles a person's chance of being in an accident! Don't believe people who tell you they drive slower and safer when high--we've done studies on this and found that people who drive high are very impaired, and the effects on driving can be detected as much as a month (!) after using the drug. 
Be safe--don't ever use any drug and then drive, and never get in a car being driven by someone who has. 
-Eric Wargo

Can marijuana kill you?

-Angel, Texas

Hi Angel - it is often said that marijuana has never caused a death by overdose. However, there are many other harmful effects of marijuana that could increase the risk of severe injury or death.  For example, there is an increased risk of having an accident while driving under the influence of marijuana.  For more information check out

-Steve Gust

can drugs cause a traumatic effect on someone?

-BirthdaYCakE, New York

Hey Cake -- absolutely!  Drugs can have both direct and indirect consequences that can be traumatic.  By direct consequences I mean the direct effect of the drug itself -- if you have an overdose, or a bad interaction between two drugs, for instance, it can land you in the hospital with some serious health consequences.  Indirect effects would be other kinds of things that the drug causes -- for example, driving while high or intoxicated can lead to traumatic and tragic consequences!

-Lori Ducharme

can drugs cause extreme hallucinations?

-sampugliese, New York
Hey there sampugliese! Thanks for this great question!  Yes, some drugs do cause hallucinations, and some drugs cause very intense extreme ones.  They can be very very frightening to experience and very confusing to a person. Check out this website for more info:
-Harold Perl

Can drugs cause people to not care for others

-lj12, New York

Yes since the damage areas of the brain necessary for awareness, so they can make someone less sensitive to others

-Nora Volkow

Can drugs cause trauma?

-Cowgirl555, New York

HI Cowgirl - yes, many drugs can cause serious psychological damage.  Some people who take hallucinogens or stimulants, for example, can have very bad reactions to them.  These can include hallucinations, panic, anxiety, and depression.  It is important to remember that drugs have many different effects and many of these effects are harmful.  For more information on how drugs affect teens please check out

-Steve Gust

Can drugs change how you think of things?

-baseballguy03, Pennsylvania
The short answer is yep!  Drugs affect the way the brain cells communicate and relays that information to the body.  Drugs can also have a very important effect on a teen's ability to learn, their relationships and also their outlook on life...mostly in a negative way.  You don't see too many happy-looking regular drug users do you? A teen's best bet is to stay drug free! Learn more about the effects of drugs on the brain and body and see questions from other teens like you!
-Dave Thomas

can drugs effect your brain

-trouscus, New York

Hi Trouscus.  Yes, drugs can affect your brain, and that is the reason people take drugs.  But not all drugs can enter the brain because the brain is protected by cells that wrap tightly around blood vessels (called a blood-brain barrier) and only let certain specifics things enter the brain.  Whether or not a drug enters the brain depends on the chemical structure of the drug.  But if someone is taking a drug to get high, you can be pretty sure that the drug is getting into the brain and changing the way the brain is working.  The real issue is whether the changes in the brain caused by a drug lasts a short time, a long time, or ends in permanent changes in the brain.

-Steve Grant

Can drugs kill you

-spongebob, New York

Hi Spongebob.  How's life at the bottom of the ocean ?  All kidding aside, some drugs are very dangerous 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. The Food and Drug Administration writes very detailed descriptions of the effects of the drug, both good and bad, that are included with every prescription. You should always read these labels to find out what the harmful effects are, use them for what they were FDA approved for, and if you have questions talk to your doctor or the pharmacist.

-Steve Grant

Can Drugs kill you?

-maryd@aslacadem, New Mexico

some can...and do. Either directly (like overdosing from heroin) or indirectly (like driving while drunk or stoned). Worth the risk??

-Jack Stein

Can drugs kill you???

-WHITEBOY101, New York

Yes, WHITEBOY101, drugs can kill you. they can kill you quickly- as in a drug overdose, or slowly, as in cancer from tobacco smoking. Your health and life are not worth experimenting with drugs. 

-Marilyn Huestis

can drugs lower your focus in school

-spongebob, New York
Hey Spongebob,
Absolutely!!!! Good question.  Drugs affect the brain and central nervous system.  During the teen years and up to about age 25 the brain in a very rapid period of development.  Doing anything that hinders the maximum development of the brain is harmful to cognitive functioning. Recent research suggests that marijuana, for example, can actually lower your IQ if you start using as a teen. Below are some links that give you more specific information.

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” -Lis Robertson

can drugs mess up your whole body

-prettygirl13, New York

Yes, but the effects will depend on the type of drug u use, the doses, and for how long

-Nora Volkow

can drugs really affect your body??

-YOLO!!!, New York
The short answer is "Yes."
The exact impact on you depends on the drug, how it is taken, and a lot of other factors.  
There is a whole lot of info on our website:
-Dave Thomas

Can drugs weeken the body? Say if an active teen around 13 who plays 3 sports can they get affecfted? xoxox billybob :)

-billybob67, New York

Absolutely billybob67! At 13 the body is still developing rapidly and drugs can interfere with normal development. Depending upon the drug, it may certainly affect training and performance in sports. For instance, some drugs may affect your ability to react correctly to different situations, slow you down, affect your vision and speed. And these are only the affects of drugs on your performance- they also affect your health!

-Marilyn Huestis

Can ecstasy kill you?

-amanda_foo, New York

Hey Amanda_foo--yep ecstasy can kill.

The geeky term for ecstasy is MDMA (3,4-methylenedioxy-methamphetamine).  It can cause the body to get rid of water and this can cause the body to overheat - called heat stroke.  The body's inability to regulate temperature is just one of the bad side-effects of ecstasy.  This is even worse and deadlier when people take ecstasy and drink alcohol at the same time, like while partying. 
Find out more on ecstasy here:
-Joni Rutter

can elderly people get addicted to cocaine?

-friendlyperson1, New York
Hey there friendlyperson1. Great user name! The short answer is YES -- elderly people can be addicted to cocaine or any other harmful and illegal drug. In fact, elderly people may even be more likely than younger adults to be harmed by many drugs. For example, the elderly may be less able to absorb and break down medications and drugs as easily as it used to (so drugs may stay in the body longer, which can increase their effects). Aging brains are also different than young ones and may be at greater risk for harmful drug effects (on memory or coordination, for example). And the elderly could be on medications for medical conditions, and these medications could interact with abused drugs in dangerous ways.
Here's some other information on cocaine if you're interested:
-Harold Perl

Can hallucinogens be placed inside an aerosol can and become weaponized? If so, is there any way we can defend ourselves against them?

-ThleduinAlkara, Pennsylvania

ThleduinAlkara, hey!  What an interesting questions.  Hallucinogens would probably dissipate or be inactivated by heat reactions before having any effects, but I don't know of any data that addresses this question.  How do you defend against this possibility?  Read more.  Do well in school.  Study science.

-Joni Rutter

Can herion kill someone once they inject it?

-alyssaskyglace, Pennsylvania

Yes- heroin use is extremely dangerous. It can result in an overdose resulting in death. Check out for more info about heroin and other drugs of abuse.

-Jack Stein

can heroin be smoked

-marshmallow, Maryland
Hello again marshmallow-- 
Quick answer. Heroin can be mixed with water and injected with a needle. It also can be smoked or snorted up the nose.
-Roger Sorensen

Can homemade cigarettes have the same effect that cigarettes sold in stores

-lj12, New York


-Cindy Miner

Can diseases from drugs be inherited to that person's children?

-Oreiter, Pennsylvania
Hey Oreiter!  This is my favorite question of the day!  It turns out that even addiction can be inherited.  In some cases this inheritance comes from small changes in the DNA sequence that makes someone more vulnerable to use drugs.  (DNA is the genetic code that has instructions for our body.)  That DNA is, of course, passed on from parent to child--making the child vulnerable, too.  
Recently, one study found something very interesting--Did you know that cocaine has been shown to affect DNA expression in the sperm--it actually affects the the way a protein called BDNF is expressed in the brain. Scientists found that the cocaine changes this protein in the sperm of drug-taking rodents, and is passed onto their male pups (yes, "pups" is how you call baby rodents).  The result of this experiment was that the male sons found cocaine LESS rewarding.  
So, the answer is pretty complicated and depends on the drug, the timing of exposure, and other individual factors.  Scientists are spending their entire careers trying to answer this very question!
Thanks for your question 
-Joni Rutter

can doing drugs lead to mental diseases

-handheldaphid, New York

yes, if you have a genetic or other vulnerability (e.g., exposure to trauma or early stress).  Marijuana has been linked to psychosis in some individuals.

-Nora Volkow

can drinking alcohol at a young age have long term affects on you?

-Donnita Rogers, Louisiana
There are lots of negative long term effects of drinking before age 21. First of all, your brain is still changing and growing, and alcohol can interfere with that development. 
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

can drinking or smoking give you brain damage? or put you in a comatose state?

-sampugliese, New York
Yes, alcohol can damage the brain and put you in a comatose state, not to mention kill you! The thinking memory, and feeling parts of the brain are all changing when we are teenagers. Alcohol can interfere with these important changes and actually shrink the thinking and memory parts.

Research tells us that drinking lots of alcohol during the teenage years can make an area of the brain called the frontal lobes smaller. The frontal lobes help us make decisions, think about things, and pay attention. Alcohol also can shrink the hippocampus, the area of the brain area that helps us learn and remember. 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.

For weeks and months after a teenager stops drinking heavily, these parts of the brain still struggle to work correctly. It's not clear whether the brain ever fully heals itself. In addition, drinking at a young age makes it more likely to become an alcoholic later in life. So, drinking when we are young could have lots of negative effects on the brain!

-Aaron White

Can drinking orange juice get rid of a hangover?

-friendlyperson1, New York

Really nothing gets rid of a hangover except for time. However, some things, like replacing lost fluids, can help ease the symptoms a little. For some people, toast and coffee is their preferred strategy. For others, it might just be orange juice. It just depends on the person. The best way to deal with hangovers is to avoid them entirely! Just don't drink!

-Aaron White

Can drug withdrawal symptoms like hallucinations cause the former drug user to kill himself/herself?

-sandy20, New York
January greetings - Sandy20. And thank you for your interesting question - and unfortunately, drug withdrawal symptoms can have major adverse effects, including anxiety, irritability, restlessness, insomnia, headaches, perspiration, racing heart and palpitations, labored breathing, shaking, nausea, vomiting, diarrhea, etc (I've worked with folks going through this - it's a really horrible experience). I can't say for sure that the hallucinations can cause suicide, but it can be one of many factors that contribute. If you know someone who is considering suicide, do not leave him or her alone. Try to get your loved one to seek immediate help from his or her doctor or the nearest hospital emergency room, or call 911. Remove any access he or she may have to firearms or other potential tools for suicide, including medications. Call the toll-free National Suicide Prevention Lifeline at 1-800-273-TALK (8255), available 24 hours a day, 7 days a week. The service is available to anyone. All calls are confidential.
-Denny Pintello

can drugs affect how you age

That is a good question.   I just heard a lecture on this topic.  Clearly drugs can make you look more aged.  Give you wrinkles, make your skin sag, etc.  But is that actually changing your age? I am not sure. But if you don't want to look old when you are not old, staying off drugs will help.   
-Dave Thomas