Note: There is no transcript for CHAT DAY 2018, which was cancelled due to the Government Shutdown initiated on January 20, 2018.

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 here.

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can you build a tolerance to alcohol?

-mikahakinen147, New York
Yes. Tolerance happens when the brain and the liver learn to function like normal even though a drug is in the body. So, over time, the person has to use more and more of the drug to get the desired effect. As a consequence, when the person stops the drug, their body functions in a way that is the opposite of the desired effects. This is called withdrawal. So, if a drug initially makes you feel good but you have to take more and more to get that feeling, you will likely feel really really bad when you stop. 
You can learn more about the effects of alcohol here:
-Aaron White

Can you build a tolerance to drugs or alchohol?

-official-_sean, Maryland
Hi there official-_sean.  I've gotta ask: is there an "unofficial" sean out there somewhere?  (just kidding!) Your question is important, and the answer is YES, absolutely.  For alcohol and many drugs, tolerance does build up.  That means that a person needs to take more to feel the effect. In fact, that is often when the really big problems start to happen.  A person keeps taking larger amounts of drugs or alcohol and the physical and mental damages keep growing larger!  Its always best not to start at all -- then you won't need to worry about tolerance.  Check out this website for more info:
-Harold Perl

Can you describe rebound symptoms?

-UNIV NorthTexas, Texas

Rebound is when u have worse symptoms after the drug leaves your brain (e.g., depression even though you may have initially taken a drug to make you feel better).

-Nora Volkow

Can you die from doing a drug once?

-Kfitzy28, Massachusetts
Sure. For example, this can definitely happen with opioids like prescription pain medications. If you take too much, it can slow your breathing to the point where it just stops.  It can also happen with cocaine.  For example, a basketball player named Len Bias took cocaine for the first time, had a heart attack and died.  His entire future career was down the drain in an instant.  Now, not every person will die from taking drugs for the first time or over time, but they definitely increase their chances of having a really bad outcome each and every time they use.  Learn more about the effects of drugs on the body and how to live above the influence at -  and
-Dave Thomas

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.

Check out what drugs can do to spiders in this youtube video!  I wouldn't want to give animals drugs like this, and I definitely wouldn't want to put them in my body!  
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 medical drugs be harmful even if used properly.

-atkinsj.19, New York

Yes, in individuals that have genetic vulnerability to their adverse effects.

-Nora Volkow

can medicinal marijuana be abused, because I see many flaws in the system

-weed machine, New York
Hey weed machine,
Great question. Yes "medical marijuana" can be abused, and probably is abused. The best way to deliver marijuana's benefits to people with real health problems will be creating actual medications from the chemicals (called cannabinoids) in marijuana, such as THC and cannabidiol. Scientists are hard at work on this.
Glad you're thinking about this. 
-Eric Wargo

Can misusing prescription drugs be almost as bad as using them without a prescription?

-defaultusername, New York

yes misuse of prescription drugs  is equally dangerous if u have a prescription vs. not having one. 

-Nora Volkow

Can my body build up tolerance for drugs?

-lms611, Massachusetts
Good question.  
Yes, that happens with most drugs.  You take them, and over time, you need more and more to get the same effects. This happens often with individuals who have chronic pain.  It doesn't mean that they are addicted to their pain medications, just means that over time their bodies have become used to the medication and at times can require higher doses to get pain relief.
-Dave Thomas

Can one drink (that has alcohal in it) effect someone who is, say 14, in a threatening way?

-aveson, California

Well, if that one drink was just a single serving, like a beer or a glass of wine, it's unlikely that a person would die but even that small amount is enough to cause small changes in balance and reaction times that could make it more likely to have an accident or get into a car crash and die. More importantly, that one drink at the age of 14 could significantly increase the risk of becoming an alcoholic later in life. 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 our skin absorb drugs

-Student6372, Maryland

Hey Student6372.  You bet our skin can absorb drugs.  For example, you can absorb drugs from "patches" like with nicotine patches, or from creams.

-Joni Rutter

can overdose of tylenol and advil have the same effects on your body as using other drugs that are known as being harmful and bad for your body and brain?

-123456, Maryland

Good morning 123456, thanks for your question!  Everyday medications like Tylenol and Advil, available over the counter, can have bad effects if people take too much or use them longer than recommended. If people take Tylenol at too high a dose or for longer than recommended, they can suffer severe liver damage. Advil can worsen asthma, for example, sometimes fatally. But Tylenol and Advil do not contain psychoactive, or 'mind-altering' ingredients, and do not produce the changes in your brain that lead to addiction. That doesn't mean that they are safe to take for long periods of time or in high doses. Also note that there are other over the counter drugs (like sleep aids) that can have surprising side effects – and need to be taken with extreme care. If you find that you need over the counter medicines frequently, make sure to consult a medical professional about how much is OK to take and what is the best medicine for your needs. Remember, if the proper amount of the drug isn't working – then it's not the right treatment for your health condition.

-Jeff Schulden

Can overdosing on trazodone cause you to be put in a concussion?

-Directioner, New Mexico

Hi Directioner...thanks for the question.  I am guessing that you are asking if overdosing can cause comas.  From what I can find, there have been reports of coma caused by trazodone.

-Joe Frascella

Can people get addicted to nicotine patches when trying to stop smoking?

-sharkesha476584, Massachusetts
Interesting question shark.
When people smoke they become addicted to nicotine, which makes it hard to quit smoking.  Nicotine patches can help people stop smoking because they provide the person nicotine.  When a person uses the patches to quite smoking, they usually will use patches with lower and lower amounts of nicotine until they don't need the patch anymore.  But even if they don't get off the patches, the patches are less dangerous than smoking. But you are right, they are still addicted when just using the patches.
-Dave Thomas

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 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