NIDA Hi! My name is Sara Bellum. Welcome 

to my magazine series that explores the 

brain’s response to drugs. In this issue, 

we will investigate fascinating facts 

about prescription drugs.

Prescription drugs are medicines that 

are prescribed to a person by his or 

her doctor to treat diseases. Some 

prescription drugs affect the brain—

especially those used to treat pain, or 

mental disorders such as anxiety or 

attention-deficit hyperactivity disorder 

(ADHD).

Doctors decide how much of a drug to 

give a person based on that person’s 

age, size, and medical history. By 

doing so, doctors oversee the safe and 

proper use of prescription drugs. Abuse 

is when someone takes a prescription 

drug without a doctor’s prescription 

or in a way or amount that is different 

from what was prescribed. Abuse of 

prescription drugs can have serious 

and harmful health effects, including 

poisoning and even death.

Mind Over Matter is produced by the National Institute on Drug Abuse, National Institutes of Health, U.S. Department of Health and 

Human Services. These materials are in the public domain and may be reproduced without permission. Citation of the source is appreciated.

NIH Publication No. 09-7423. Printed 2009

For more information, visit:

www.teens.drugabuse.gov

Follow the Directions

Surprising Facts

The Search Continues

Prescription painkillers, drugs to treat sleep disorders, anti-anxiety drugs, and 

stimulants are powerful drugs. It is important to follow a doctor’s, health care 

provider’s, or pharmacist’s instructions about how much to take and what things 

to avoid. For example, taking more than the prescribed amount of any prescription 

drug can lead to an overdose. People who overdose may vomit or even fall into a 

coma, depending on the drug. In addition, a person 

may have serious side effects from mixing prescription 

drugs with other medicines, over-the-counter drugs, 

or alcohol.

There is much that scientists have yet to 

discover about the effects of prescription 

drugs on the brain and body. Maybe you 

will make the next big discovery! Until 

then, follow me—Sara Bellum—in the other 

magazines in my series, as we explore how 

drugs affect the brain and nervous system.

• Prescription painkillers can cause nausea 

and vomiting.

• Mixing anti-anxiety or sleep disorder 

drugs with other drugs, particularly 

alcohol, can slow breathing, slow heart 

rate, and possibly lead to death.

• Abusing stimulants while taking a cold 

medicine with decongestants can cause 

dangerous increases in blood pressure 

and irregular heart rhythms.

The Brain’s Response to

Prescription Drugs

National Institute on Drug Abuse

To learn more about prescription drugs and other drugs of 

abuse, or to order materials on these topics, free of charge, in 

English or Spanish, visit the NIDA Web site at

www.drugabuse.gov or contact the

DrugPubs Research Dissemination Center

at 877-NIDA-NIH (877-643-2644;

TTY/TDD: 240-645-0228).
Neurotransmitters

Neuron

Receptors

Neuron

Marijuana 

Opiates 

Inhalants 

Hallucinogens 

Anabolic Steroids 

Stimulants 

Nicotine 

Methamphetamine 

How Do Prescription Drugs Work in the Brain?

Types of Prescription Drugs

Prescription Stimulants

Prescription Anti-anxiety Drugs

Prescription drugs change the chemistry of the brain. The brain is made up of about 

100 billion neurons, also known as nerve cells. Neurons communicate with each 

other by using chemical messengers called 

neurotransmitters. There are many types of 

neurotransmitters, and each one carries a specific 

message. Neurotransmitters deliver their messages 

by attaching to special places on nerve cells called 

receptors. Prescription drugs act by mimicking 

certain neurotransmitters. Below, we will learn 

more about specific types of prescription drugs that 

can be dangerous when abused. Prescription stimulants cause neurons to 

release two neurotransmitters: dopamine 

and norepinephrine. Dopamine carries 

messages in the brain about feeling good. 

Norepinephrine is a chemical in the brain 

that helps people pay attention and focus. 

Doctors often prescribe stimulants to help people 

with attention-deficit hyperactivity disorder (ADHD). Many 

scientists believe that in people with ADHD, the dopamine system 

works slightly differently than in people without the disorder. Prescription 

stimulants can bring brain dopamine function back to normal and help people with 

ADHD focus better and pay more attention.

Stimulants can be addictive and dangerous when abused. In fact, abusing stimulants 

can cause chest pain, stomachaches, and feelings of fear 

or anger. They can also cause seizures and 

irregular heartbeats that can cause death. 

Doctors may prescribe drugs to help people with anxiety disorders. Some antianxiety drugs affect the neurotransmitter GABA. 

After taking anti-anxiety drugs for a long time 

and suddenly stopping, a person may experience 

withdrawal symptoms such as anxiety, shakiness, 

headache, dizziness, and, in extreme cases, 

seizures. Abusing prescription anti-anxiety 

drugs can result in addiction or overdose. 

Prescription painkillers are powerful drugs that reduce pain. These drugs are very 

helpful to people with severe pain from injuries, and cancer and other diseases. 

Prescription painkillers attach to particular sites in the brain called opioid receptors, 

which carry messages about pain. With proper use of prescription painkillers, the 

pain messages sent to the brain are changed and are no longer perceived as painful. 

Patients who are prescribed painkillers for a long period of time may develop a “physical 

dependence” on them. This is not the same as addiction. Physical dependence happens 

because the body adapts to having the drug around, and when its use is stopped abruptly, 

the person can experience symptoms of withdrawal. That is why these drugs are carefully 

monitored and should be taken or stopped only under a doctor’s orders.

Prescription painkillers can be highly addictive when used improperly—without a 

doctor’s prescription or in doses higher than prescribed. Addiction means that a person 

will strongly crave the drug and continue to use it despite severe consequences to 

their health and their life. Prescription painkillers also affect the brain areas controlling 

respiration, and when used improperly (or mixed with other drugs) can cause a severe 

decrease in breathing that can lead to death.

Prescription drugs for sleep disorders increase levels of a neurotransmitter named 

gamma-aminobutyric acid (GABA). GABA sends messages that slow down bodily 

functions and make a person feel drowsy. 

Prescription drugs for sleep disorders may have side effects, including headache, muscle 

aches, daytime sleepiness, trouble concentrating, and dizziness. Prescription drugs for 

sleep disorders should never be mixed with any other drugs that cause drowsiness, 

such as over-the-counter cold medicine, alcohol, or painkillers. If combined, they can 

slow a person’s heart rate and respiration, which can be fatal. 

Prescription Painkillers

Prescription Drugs for Sleep Disorders