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 insects and animals get addicted by drugs?

--A, Massachusetts

Totally, -A-.  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

Can it hurt me to take Tylenol and Advil at the same time?

-Eileen Marshall, Iowa
Probably not.  They are similar types of pain killers. But they typically are not given together.  If you take one and it works, there aren't advantages to taking the other.  But if you have pain, I suggest you get some medical advise from a doctor, and try that instead of experimenting on yourself.
-Dave Thomas

can long term drug abuse give you mental health problems such as bipolar disorder, BPD, or OCD?

-skpmb, Maryland
Good morning!
This is a great question. Let me try to explain the complex connection between drugs and mental illness. To answer your question directly, there is no clear evidence that long term drug abuse "causes" BPD or OCD. However, mental illnesses such as depression, bipolar disorder, anxiety disorders, etc. coexist or in some cases, appear before one develops a substance use problem. You may also want to know that long-term use of drugs are likely to result in other mental illnesses such as psychosis, depression, anxiety and in some cases suicidal thoughts.
Thanks a lot for asking! 
-Geetha Subramaniam

can marijuana affect you right away?, New Jersey

Hi, Yes it can if you smoke it. We did a study and showed that people could feel the affects immediately during the first puff on a marijuana cigarette. You feel your heart rate increasing right away and the way you think and feel becomes affected.

-Marilyn Huestis

can Marijuana be baked into food? and how can you tell it is in the food?

-hashtagmadswag, New York

Hello there hashtagmadswag, Yes, marijuana can be baked into food and you may not be able to tell it's in the food before you eat it. There's really no way to tell food has marijuana in it just by looking at it. You wouldn't feel the effects until much later- 2 to 4 h after eating the food. The affects would be milder than if you smoked the marijuana but effects can last longer. Thanks for your question.

-Marilyn Huestis

Can marijuana cause cancer

-20n62604, Pennsylvania
20n62604--Wow! This is a great question, and one that is currently being studied extensively. We have learned a lot about cigarette smoking and we are only just beginning to learn about marijuana. Remember, it took a long time for us to understood the connection between cigarette smoking and illness.  Now we know, however, that cigarette smoking results in more than 443,000 deaths in the US each year, and an additional 8.6 million people suffer from serious illnesses including cancer caused by smoking. There are studies ongoing where researchers are now investigating whether there is a similar link between smoking marijuana and cancer. Stay tuned!
-Will Aklin

Can marijuana cause lung cancer?

-Blue Ivy, Massachusetts

Great question Blue Ivy--unfortunately, we don't yet have an answer.  Marijuana smoke contains many of the same carcinogens and other toxins or poisons as tobacco smoke, and people tend to inhale deeply and keep the smoke in their longs for longer periods than tobacco smoke.  But studies in people have not been conclusive in showing higher rates of lung cancer in those who smoke only marijuana (and not tobacco).  Marijuana does increase the risk for other respiratory illnesses, like bronchitis, and produce increased coughing and phlegm production.

-Susan Weiss

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 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 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