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.

You searched for tolerance and dependance and addiction. Showing 1 to 30 of 1605 questions.
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is it true that aderol lowers your tolerance to drugs and alcohol

-herro im yerro, New York
Hmm. You are making me think on this question.
Adderall is a stimulant drug. It has good medical uses for treating ADHD and for some patients in the emergency room.
With long-term use, a person can become tolerant to Aderall's effects.Aderall and other stimulants produce tolerance by similar biological mechanisms, so someone who is tolerant to one may well be tolerant to others. However, aderall and alcohol produce tolerance by different mechanisms, so tolerance to one wouldn't necessarily affect tolerance to the other. Similarly, with other drugs, whether there was a shared tolerance would depend on how similar the biological mechanisms are.
-Roger Sorensen

Sparta Middle School -Why are alcohol and drugs so addicting?

-CFPC, New Jersey
Great question, CFPC!  There are lots of factors contributing to drugs' and alcohol's addictive properties, but a major reason that they are so addicting is that drugs of abuse are "psychoactive" -- that is, they have their main effect on the brain, which results in the reinforcing or pleasurable feelings one experiences. Drugs specifically have their effect on the pathway within the brain called the brain reward system and release the brain chemical, dopamine, within this reward system.  The effects on this system result in drugs' addictive properties. People tend to like the feeling of euphoria that drugs can initially give, which in turn, can lead to addiction.
-Joe Frascella

Sparta55: Is mixing drugs and beer good or bad?

-AnnmarieS., New Jersey

Bad. All drugs disrupt brain function in some way. Alcohol disrupts most brain functions. So, combining alcohol with most other drugs leads to larger impairments and more danger. 

-Aaron White

Sparta Middle School -How much does it take to overdose on heroin, cocaine, and crack?

-CFPC, New Jersey

depends on the person--people have different sensitivities; also depends on the person's drug use history--people can develop tolerance to a drug's effects meaning they need more to achieve the same effect.  This would also make them less likely to overdose on a drug than a naive users.

-Susan Weiss

Sparta Middle School -If tobacco can kill you and marijuana can’t, why is tobacco legal and marijuana illegal?

-CFPC, New Jersey

they have different risks--marijuana can affect your ability to learn and remember, can affect your mental health, and like tobacco, it is addicting.  Also marijuana can kill--not directly, but indirectly through car accidents (especially when combined with alcohol).  

-Susan Weiss

Sparta20: What is the main chemical that causes addiction?

-AnnmarieS., New Jersey
Hey AnnmarieS!  Drugs cause the brain to release a substance called dopamine. But these feelings are short-lived. Dopamine--a chemical in the brain called a neurotransmitter--is closely involved in brain function, which makes it a key player in drug abuse and addiction.  Dopamine is present in regions of the brain that control movement, emotion, thought, motivation, and feelings of pleasure. Eventually, people become focused on obtaining and using drugs at every opportunity--although recreating the initial high becomes nearly impossible.  Another way that drugs change the brain is to affect the ability to make decisions, such as judging what's important, what's healthy, and what's dangerous. The compulsive seeking and using of drugs even in the face of potentially devastating and deadly consequences is the essence of addiction.
 Thanks for a great question.  You'd make a good scientist!


-Joni Rutter

Sparta19: Can a drug or alcohol give you a really bad disease and then kill you?

-AnnmarieS., New Jersey

Hey AnnMarie - absolutely!  I can think of a couple examples right off the top of my head.  For example, chronic (long-term) over-consumption of alcohol can lead to cirrhosis of the liver -- it literally kills your liver cells, and you can't live without a liver!  Also, injection drug use is a known risk factor for contracting hepatitis C.  And alcohol and drugs can impair your decision-making and lead to an increase in risky sexual behavior, which increases your risk of exposure to HIV/AIDS.  I'm sure you already know that smoking causes lung cancer. Thanks for your question and take care!

-Lori Ducharme

Sparta3: What is in alcohol and why does it get you drunk?

-AnnmarieS., New Jersey

Alcohol is a very simple molecule made when yeast, a type of fungus, eats sugar and gives off alcohol as a waste product. Most alcohol that people drink is made by putting yeast into a mash of fruits or vegetables. The yeast eat the sugar in the mash and alcohol is produced. It's still a little bit of a mystery how alcohol works, but in general it interferes with the ability of brain cells to work properly, making it harder for a person to walk, talk, think and make good decisions. We call this condition, "drunk". 

-Aaron White

Sparta Middle School - What is in alcohol and why do you get drunk?

-CFPC, New Jersey

Alcohol, specifically ethyl alcohol, is the ingredient in alcoholic beverages that gets people drunk. Getting drunk happens when enough alcohol gets into the brain to disrupt activity in areas that control thinking, feeling, balance and coordination, decision making and other important functions. When people are drunk, they tend to take more risks and make bad choices due to the effects on the frontal lobes of the brain. Due to effects on the hippocampus, another area of the brain, some drunk people don't remember what they did when they wake up the next day. Alcohol disrupts the cerebellum in the back of the brain, which makes drunk people stumble around and lose their balance. 

-Aaron White

Sparta24: What is crystal meth and what is it made from?

-AnnmarieS., New Jersey

Hey! Thanks for the question. Meth is a white, bitter powder and easily dissolves in water or alcohol. It is made from chemicals---not plants. Sometimes it's made into a white pill or a shiny, white or clear rock called a crystal. Although most of the meth used in the United States comes from “superlabs”—big illegal laboratories that make meth in large quantities—it is also made in small laboratories using inexpensive, over-the-counter and often toxic ingredients like drain cleaner, battery acid, and antifreeze.Some health experts think it is the worst drug you can take---it can really destroy a person---from the inside out. More here:

-Ruben Baler

what are some ways to try and get over an addiction?

-maria1029, New York
Hi maria1029!  The best treatment depends on the needs of the person, since drug abuse and addiction have so many dimensions and disrupt so many aspects of a person’s life. In general, talking to a parent or a trusted adult (like a teacher or minister) is a good first step in getting treatment.  Drug abuse treatments typically include behavioral counseling, often accompanied by medicines. Here's a link with more information, including questions to ask when seeking treatment:
Of course the best way to get over an addiction is to never start using drugs Here's a pretty cool website that can give you more info on identifying and managing drug addiction:
-Harold Perl

Sparta7: If there was a person that was addicted to drugs and now isn't, is there a possibility they will become addicted again?

-AnnmarieS., New Jersey
Great question, Sparta7. Yes, there is a possibility that this could happen. People that have been addicted to drugs can relapse, even after many years of complete abstinence. It depends on many factors, such as for example the environment, family situation and personality, but it's safe to say that it would be better to stay away from any contact with the drug. For more information, see:
-Anto Bonci

How long does it take the body to build up a tolerance on drugs?

-sophiet, New York
Hi Sophie
It really depends on the drug and how they are taken. In general, tolerance can start real quickly.  Sometimes after the first dose.   When someone becomes tolerant they have to keep taking more and more to get the same effect.  This is part of the process that leads to addiction....
-Dave Thomas

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

My best friend has been dealing with marijuana addiction and i dont know how to help her. she is falling behind in school and is doing it just to impress some guy what should i do???

-cakecakecake, New York
Cake,  This is a difficult situation for you and I applaud your desire to help your friend.  The first thing you can do is listen to what your friend is saying about their drug use including why they are using. It is always a good idea to encourage your friend to seek advice from a trusted adult like a parent, teacher, coach, parent of a friend.  If your friend is not ready for help, don't give up. Keep reaching out and hopefully someday soon she will be ready to get help. And remember to take care of yourself. Supporting someone with a substance use problem can be stressful!!
More information on drug treatment can be found at: 
-Redonna Chandler

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

What does it feel like to be on drugs for an extended length of time, and then stop altogether? Do the automatic urges often overwelm one so much that permanent or just temporary harm can overtake a person?

-Sorrelosophic, Maryland

Hi Sorrel - thanks for your question.  If drugs are taken for a long time, they will often stop having the same effects.  This is called tolerance.  Related to tolerance can be the development of dependence or addiction.  Not all drugs cause dependence, but the ones that do result in feelings like you describe, having urges, feeling strange, sometimes having severe and life-threatening withdrawal.  These symptoms go away quickly for most people. If you want to ask about getting substance abuse treatment for yourself or for someone you care about, call 1-800-662-HELP 24/7.  Or, you can go to to find information about treatment centers in your area.

-Steve Gust


-#SWAG, New York
Hi there #Swag
Purple drank refers to a mixed drink containing prescription-strength cough syrup (which contains drugs like codeine and promethazine) and a soft drink like sprite or mountain dew. It used to be popular in hip hop communities in the south. The drugs in this beverage are extremely dangerous.
be smart
-Ruben Baler

Diffrence between acid and mushrooms?

-tmac316, Maryland

Well one is synthesized in the lab and the other is a mushroom.  That is one difference.  But both are hallucinogens.  The hallmark of these drugs, which include LSD, MDMA  (methlyenedioxymethamphetamine, Ecstasy), and PCP (phencyclidine) is causing distorted perceptions and hallucinations (seeing and hearing things that are not there).

For more info, see

-Dave Thomas

Who created drugs and alcohol?

-Lu_nation, New York

In many cases, nature creates drugs and alcohol. If you put a bowl of fruit somewhere for long enough yeast will land in it, causing fermentation and the production of alcohol. However, humans create some drugs in labs, too.

-Aaron White

are drugs like viruses and attack cells

-ra, New York
Dear ra, that is a great analogy. Drugs do act like viruses that impact the brain in a very significant way. Drugs have strong behavioral, chemical and emotional effects of drugs. For example, drugs contain chemicals that take over the communication system in the brain, and therefore, interrupts the way in which nerve cells send, receive and process this information. Drugs, in other words, imitates the brain's natural chemical signals, and also intensifies the 'reward' circuit of the brain. Drug addiction actually changes the brain and compulsive drug seeking is part of it, this is why addiction is such a devastating disease. 
Stay healthy! 
-Will Aklin

Do all drugs and alcohol cause hallucinations and epilepsy?

-felisa.holden, Virginia
Hi Felisa.
thanks for the question!
The answer is no: specific drugs have specific effects. you can visit these sites to find out what drugs have specific neurological and mental health effects.
all the best.
-Ruben Baler

what are the risks and dangers to drugs and why do people do it

-ikillforbf3, Maryland
Good morning, ikillforbf3. Drugs affect the body in many ways, and can affect the brain development of youth. Using drugs can impact a person's health, and can affect social relationships, academic success and can cause legal consequences. There are many reasons why people use drugs, including biological factors, such as genetic risk, and environmental factors, such as a family history of drug abuse. But having a risk factor does not mean that a person will use drugs. Check out this short animation on factors that contribute to drug abuse and addiction.
-Belinda Sims

Would Mental Health and Illness be the main cause of drugs and alcohol?

-AshleyP-P2, Texas
Hello there AshleyP-P2!  Thanks for the interesting - and actually, complicated question! The short answer is no, mental illness is not the main cause of substance abuse, yet it may contribute. At NIMH, we are finding that symptoms of mental illness can emerge during childhood and adolescence. Sometimes, these symptoms can be confusing and difficult to deal with, so some folks try drugs and/or alcohol to feel better (temporarily). NIDA has a great resource to check out: which might provide additional info. 
-Denny Pintello

what drug is the most addictive? And why?

-jalonso, New York

Thanks for your question!  This question is complicated so the answer is not so simple. Scientists are reluctant to rank drugs in order of addictiveness and harm. There are just too many variables that would need to be considered: like one's genetics, the environment that one is in, and developmental age when the drug is taken, all of which play important and changing roles in determining to what extent abuse of a particular drug will lead to addiction.

The fact that it is almost impossible to rank drugs does not mean that we cannot identify factors that contribute to or influence the addictiveness of a particular drug. One thing we do know, once you try drugs, you have a higher risk of becoming addicted. For more info on addiction, check out

-Joe Frascella

does weed lower serotonin levels? how about alcohol and LSD?

-walterjohnson, Maryland
Best question of the day so far, walterjohnson!  Marijuana can actually increase serotonin levels in certain areas of the brain that are important for mood and anxiety.  This suggests that repeated exposure to marijuana may be associated with those disorders.  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.  LSD looks a lot like serotonin and the brain mistakes the two chemicals--this means that LSD acts as a neurotransmitter rather than serotonin and that is NOT good. 
You can check out this great webpage on the NIDA for teens site that explains what effect drugs have on the brain:
-Joni Rutter

i have a family member who drinks beer everyday and doesn't drink anything else yet now it seems like they are perfectly fine. is there a chance to become immune to the side effects of alcohol and drugs

-maya101, New York
It is possible to develop what's called tolerance, which means a person can drink large amounts of alcohol without appearing, or even feeling, intoxicated. However, it's important to know that tolerance can be a sign of alcoholism. Only someone trained to evaluate a person's drinking habits can tell for sure if they have a problem. You should talk to an adult you trust, like a teacher, doctor, or family member.
Here are some symptoms and problems that indicate someone should seek out help:

· Tolerance - needing to drink greater amounts of alcohol to feel its effects

· Withdrawal - not drinking causes nausea, sweating, shakiness, anxiety

· You drink more or for longer periods of time than you intend to

· You have an ongoing desire to control your drinking, but are unsuccessful

· You spend too much time getting alcohol, drinking, and recovering from hangovers

· You give up important activities like being with friends, playing sports, etc.

· You drink even if it causes physical problems, or makes problems you already have worse

Here is a link to further information about the signs of alcoholism:


-Aaron White

why are adults adidactic to meth and other drugs

-jadeiscool, California

Thanks...good question ! drugs "hijack" the brain resulting in a compulsive desire to use over and over despite negative outcomes. This is the very definition of addiction!

-Jack Stein

are alcohol and smoking bad combinations?

-devondonahue, New York

Both alcohol and nicotine can produce nausea and some people get really sick from the combination. If you meant smoking marijuana, both can impair balance, coordination, reaction times, decision making and attention, making the odds of being injured or making back choices higher if you combine the two drugs. 

-Aaron White