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 different drugs do different things. Does it affect your brain?

-KevinC, Texas

Hi Kevin, Yes and Yes. Some drugs are stimulants (methamphetamine) others are sedatives (heroin) and some are psychoactive (LSD). They affect different cells in the brain, and different brain areas and brain connectivity. What they share in common is the ability to create a sensation of pleasure or reward which reinforces and increases the desire to have more. More information is here:

-Roger Little



TY THE FLYEST- hey there...

Dogs can get high off drugs, but they can also get very sick. Dogs much prefer to be taken out for a walk instead. 


-Joni Rutter

Can doing drugs kill a baby before its born? (Not including being prematurely born)

-BallislifeMD, Maryland

We know that drugs can affect babies before they are born. Drugs are passed from mother to fetus. These include alcohol, stimulants like cocaine, and heroin as babies are born with fetal alcohol syndrome, stimulant syndrome, and heroin dependence.  We have no data on whether fetuses who die before birth did so because of drug exposure.  But it does not seem fair to expose an innocent human to these drugs.

-Nancy Pilotte

Can doing drugs trigger an underlying mental or personality disorder? And if so, which drugs are most likely to do sotion

-lc, Maryland

lc - great question! We are still sorting out the science of what comes first - mental illness or drug use, yet research is showing us that it is possible that people who develop symptoms of mental illness or disorders start taking drugs in an attempt to medicate themselves. Unfortunately, it doesn't help with the symptoms, and folks end up feeling worse. Whatever symptoms appear first, it's important to treat all mental illnesses at the same time. The best thing to do is go to a doctor who can provide treatment.
Regarding your second question, here's a link to more on which drugs can cause mental health problems:

-Denise Pintello

Can doing drugs, especially alcohol and marijuana, enhance or lead to depression at all?

-lc, Maryland

Hello 'Ic'! Thanks for your great question. Research has suggested that depressive symptoms are linked to the initiation of drug taking in adolescents. Check out this link for some information about it:

-Bethany Deeds

Can drinking underage affect the brain

-sofia12, Florida

Yes, alcohol affects every part of the brain. 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. It can also affect the part of the brain that controls our movement, making it more difficult to walk and focus.Teens who drink too much risk suffering lingering problems with attention and memory. 

-Aaron White

can drug addiction be over come on your own or do you need help?

-BryceR, Texas

Hi BryceR,

You have probably heard that some people who smoke can quit "cold turkey". These people have extremely high will-power. Unfortunately, these poeple are few and far between. Once you become addicted to alcohol or drugs, it is very hard to quit on your own. We are doing  research to develop and improve behaviroal and medicine treatments to help addicted people stop using. A combination of both treatments has been shown to be the best approach for treating addiction.

If you know anyone who wants to quit taking drugs, here is a website that gives information on local treatment programs throughout the Nation:

-Roger Sorenson

can drugs affect my cell division process

-Fallout, Michigan

Hi Fallout - Gold star question!  In general, addiction researchers study effects of drugs on the brain, and mature neurons don't divide.  However, some reports found that a byproduct of cocaine metabolism hinders the development of new nerve cells by interfering with a specific protein, cyclin A, which regulates cell division. More research needs to be done on this question to understand the effects of other drugs of abuse.  I hope you become a scientist, Fallout, and try to help us figure this out!

-Joni Rutter

Can drugs affect personality?

-Jju, Maryland

Hello Neighbors from Maryland!  As a result of decades of scientific research, we know that addiction is a disease that affects both the brain and behavior. Here is an example--Marijauna. Long-term use of this drug can  lead to a series of attitude and personality changes, known as “amotivational syndrome.” This syndrome is characterized by a diminished ability to carry out long-term plans, a sense of apathy, decreased attention to appearance and behavior, and decreased ability to concentrate for long periods of time. These changes can also include poor performance in school.
Here's a link for more information:

-Bethany Deeds

Can drugs affect your eye sight?

-AlynaG, Texas

Hi Alyna! Drugs can certainly affect your perception of sight. Hallucinogenic drugs (LSD, peyote, etc) can make you see things that aren't there, for instance. There is also some evidence that cocaine use can contribute to developing glaucoma, an eye disease that affects sight. For instance, one study showed former cocaine users were found to develop glaucoma on average 20 years earlier than non users, even if they no longer took the drug.

-Joseph Frascella

can drugs be different flavors

-ncampion, New Hampshire

Certain drugs such as cigarettes and e-cigarettes can come in different flavors. I just read yesterday that there are over 7000 different e-juice flavors!  Don't let the fun, fruity flavors fool you!  Drugs can be extremely harmful to your body and can have severe consequences.

-Albert Avila

Can drugs be used in a positive way?

-JDogJules, Maryland

Hi JDogJules- Good question!! And the short answer is that it depends on various factors.  It is important to know that ALL drugs can be harmful, except when taken as prescribed by a doctor.  Drugs have negative effects on brain functioning, on one's ability to make good decisions, and on one's health in general.  Below is some information on the effects of specific drugs.  It is important that you and your friends have the FACTS on the negative effects of drugs.

-Albert Avila

Can drugs cause depletion?

-Kearsarge, New Hampshire

Hi Kearsarge. Not sure what you mean, but if you are asking about depletion of brain chemicals known as neurotransmitters, the answer is yes,  For example, cocaine and methamphetamine are both stimulants and these can cause depletion of dopamine.  Ectasy can cause depletion of serotonin in the brain.

Hope this helps, and if you are interested in learning more, check out

-Joseph Frascella

Can drugs cause internal bleeding?

-tamyra221344, Georgia

Dear tamyra221344 -- Sorry for the delay on answering your question-- we've been busy!  Luckily, internal bleeding is not a big problem in drug abuse. In general, drugs prefer to wreak havoc on the brain.

-Joni Rutter

Can drugs cause internal bleeding?

-tamyra221344, Georgia

The category of abused drugs does not usually have this as a side effect. Internal bleeding is more apt to occur in people who are prescribed heparin, aspirin, Coumadin (warfarin) or other blood-thinning agents and these are usually recommended only for people who have atherosclerosis or other serious heart disease.

-Nancy Pilotte

can drugs effect a person's emotions?

-Mariah, Ohio

Drugs can impact emotions.   When one is high, they might get euphoric.  When they come down, they might get depressed or anxious.  Kind of depends on the person and drug used.   In general what goes up, must come down.  Other effects on emotions depend on the particular drug that is abused.  For more information, see:


-Dave Thomas

Can drugs effect your body and brain and also alcohol?

-KevinC, Texas

Great question Kevin,
Absolutely, drugs and alcohol (which, by the way, is a drug) affect many parts of your body and brain. In fact, that is exactly how drugs work, both illegal and legal drugs, by affecting your brain and body. Some of those effects may be beneficial and other harmful. The good effects is the reason why a doctor will prescribe a drug, and the bad effects is why it is important to read the label and talk to the doctor about how the drugs are affecting you. On the other hand, illegal drugs have been determined to have severe bad effects--not only addiction, but damage to many organs and tissues in the body. Excessive alcohol use can damage the liver--a disease called cirrhosis; stimulants can lead to heart problems, and smoking can damage the lungs. Here's more facts from our website:

-Steven Grant

can drugs effects your brain how your friend if they drug addiction

-lionsadv, Texas

lionsadv...what??? I hope this answers your question: Drugs disrupt the interaction of nerve cells and the neurotransmitters that are released from them. Neurotransmitters help to control behavioral, perceptual, and regulatory systems, including mood, hunger, body temperature, sexual behavior, muscle control, and sensory perception. Other types of receptors in the brain are important for the perception of pain, responses to the environment, and learning and memory. Check out our booklet Drugs, Brains and Behavior- The Science of Addiction at If you feel your friend is in a crisis, you can call 1-800-273-TALK (8255) anytime 24/7. 

-Joni Rutter

Can drugs harm you even if you do it once in a while? Like once every six months?

-BrandonL, Texas

Most drugs can be fatal if taken in high enough quantities. You could overdose even if you only use rarely but the dangers of drug use increase the more often you use and the higher doses you use.

-Maureen Boyle

can drugs infect the feet?

-PatriotsFan#1, Georgia

Hi patriotsfan.

no, unless you inject them in there...
do you?


-Ruben Baler

can drugs kill you

-Denayzha, Georgia

Yes, in high enough doses most drugs can be lethal.

-Maureen Boyle

can drugs kill you

-Denayzha, Georgia

Yup, drugs can kill you. Either from immediate side effects that cause death (like a heart attack or stroke), or from secondary causes, like a car crash while under the influence of a drug, or from the carcinogens (harmful) chemicals in some drugs, like cigarettes, which can cause cancer and kill you.

Thanks for the question, Denayzha!

-Joseph Frascella

Can drugs lead to depression?

-JamieT, Texas

Hi Jamie. Chronic use of some drugs of abuse can cause long-lasting changes in the brain, which may lead to paranoia, depression, aggression, and hallucinations.

-Joel Sherrill

can drugs like weed and cocain actualy screw up easy every day things?

-BONG_BOY, Maryland

thats exactly what drugs do as they have their direct affect on the brain!

-Gaya Dowling

can drugs make people go crazy

-0040853, Florida

Hey there 0040853!  can i call you "853" for short?

Thanks for your great question.

I'm guessing that you're thinking about whether drug use can cause mental health problems. In fact, some researchers are asking the same question themselves! We don't have a lot of scientific data yet, but early indications suggest that marijuana can worsen people's depression or anxiety over time.And thats not a good thing! 

Also, we are looking to see whether drug use can make other mental illnesses such as schizophrenia more likely.

Check out our website for more info:

-Harold Perl

can drugs make people go crazy

-0040853, Florida

Yes.  Many drugs cause mental symptoms.  Paranoia and hallucinations are common when people take high doses of cocaine or methamphetamine.  Even marijuana can cause anxiety, paranoia, and may make people susceptible to serious mental illness.  And alcohol can cause brain damage and mental illness---especially when taken over a long period of time.

-Wilson Compton

can drugs make people go crazy

-brecks, Texas

Yes, drugs can trigger pscyhosis (people think other are trying to kill them and might hallucinate).  Some drugs trigger these episodes more frequently than others (e.g., methamphetamine).  Marijuana at high doses can also trigger psychosis and in those that are vulnerable, might lead to schizophrenia

-Nora Volkow

:33 > Dear scientists, do any of you play any of the popular games like Call Of Duty: Black Ops, Amnesia, or anything of the sort?

-arsenicCatnip, Texas

I just asked the room and there were at least five people in the room who said yes :)

-Maureen Boyle

:33 > How bad can the hallucinations get when you take hallucinogenic drugs?

-arsenicCatnip, Texas

I am not sure about scientific studies on this, but people report having "bad trips" which can last for many hours and are just not fun.   From the descriptions, they sound awful and once on a "bad trip," the peron is stuck and suffers for a long time.  And the "bad trip" varies from person to person and can even be different for the same person from one use to another.

-Dave Thomas

:33 > Is catnip like marijuana fur cats or purrhaps you do not know the answer to this question?

-arsenicCatnip, Texas

Hey arsenicCatnip- let me paws for thought.... Here's what we know about catnip-- it is not addictive or psychoactive. Catnip (from the plant Nepeta cataria) DOES cause most cats to act strangely: they roll around, shake their heads, rub against things, and try to get the plant all over their bodies. Interestingly, cats are only affected when they smell it - it has NO EFFECT if they eat it. It appears that catnip has little or no psychoactive effects in people.

-Joni Rutter