All drugs, regardless of whether they are illegal, prescription, or over-the-counter (available without a prescription), change the body’s function or chemistry and can be harmful. OTC drugs are available to the public with the understanding that they will be used only as directed and to treat a particular ailment.

For example, the common pain reliever, ibuprofen (more commonly known as Advil), can cause kidney damage if taken for prolonged periods. Just like with any drug, overdoses from over-the-counter medication can occur. From 1999 to 2004, there was a seven-fold increase in cases related to the abuse of DXM reported to poison control centers nationwide. Most of these cases were among 15 and 16 year olds. The health risks of abusing OTC cough and cold remedies include impaired judgment, nausea, loss of coordination, headache, vomiting, loss of consciousness, numbness of fingers and toes, abdominal pain, irregular heartbeat, aches, seizures, panic attacks, psychosis, cold flashes, dizziness, diarrhea, addiction, restlessness, insomnia, high blood pressure, coma, and death.

An overdose on over-the-counter drugs can vary greatly depending on what other drugs they are mixed with, the amount of drugs taken, and how they are taken. Some over-the-counter drugs can cause serious problems or even death if used incorrectly. The only safe way to take over-the-counter medications is exactly as directed on the bottle and to treat the symptoms for which they are intended.

ALL drugs are chemicals that affect the body. But some people don’t realize that prescription drugs and over-the-counter drugs can be equally as dangerous as street drugs. The very reason prescription drugs require a prescription from a doctor is because they are powerful substances and need to be regulated and taken under a physician’s care to ensure that patients take them safely.

Even if a person is prescribed a medication, taking more of that drug, or taking it more often than recommended, is dangerous. The most recent research on deaths in the U.S. due to unintentional poisoning over a five-year period shows that nearly all poisoning deaths are attributed to prescription and illegal drugs. Prescription opioids such as hydrocodone, oxycodone, and methadone account for the greatest percentage of deaths from prescription drugs.1

Side effects of prescription drugs, including painkillers, depressants, and stimulants, include respiratory depression, dizziness, slurred speech, poor concentration, feelings of confusion, increased heart rate and breathing, excessive sweating, vomiting, tremors, anxiety, hostility and aggression, suicidal and homicidal tendencies, convulsions, lack of energy, inability to concentrate, nausea and vomiting, apathy, heart attacks, addiction, coma, and death.2,3

Prescription drugs can also be addictive. Between 1995 and 2005, treatment admissions for abuse of prescription pain relievers grew more than 300 percent.4

Additionally, getting prescription drugs without a prescription is illegal and may subject a person to arrest and prosecution. Regardless of how you acquire a prescription medication, using these types of drugs without a valid prescription and medical supervision is unsafe and illegal.

1. Treatment Episode Data Set (TEDS). 2007 Treatment Episode Data Set, 1995 to 2005
   National Admissions to Substance Abuse Treatment Services, Substance Abuse and Mental Health Services Administration.
   View Source [↩]
2. National Kidney and Urologic Diseases Information ClearinghouseYour Kidneys and How They Work
   November 2005.
   View Source [↩]
3. Bryner, Wang, Hui, Bedodo, MacDougall & Anderson. 2006. Dextromethorphan Abuse in Adolescence, An Increasing Trend: 1999-2004. 
   Archives of Pediatric and Adolescent Medicine.
   View Source [↩]
4. Better Health Channel. Drug overdose
   2006
   View Source [↩]

Marijuana affects everyone differently. Some people seem to be able to use it for a while, while others experience negative consequences and can get hooked early on. Remember, we never know when addiction actually starts, and a person’s genetics seem to play a major role, meaning that some people get addicted much faster than others. The bottom line is that no matter how in control someone may seem, there are chemical changes occurring in his or her brain, and sooner or later, it can affect his or her ability to perform mentally and physically.

Chronic exposure to drugs of abuse disrupts the way critical brain structures interact to control behavior—behavior specifically related to drug abuse. Just as continued abuse may lead to tolerance or the need for higher drug dosages to produce an effect, it may also lead to addiction, which can drive an abuser to seek out and take drugs compulsively. Drug addiction erodes a person’s self-control and ability to make sound decisions, while sending intense impulses to take drugs.

We know that the same sort of mechanisms involved in the development of tolerance can eventually lead to profound changes in neurons and brain circuits, with the potential to severely compromise the long-term health of the brain. For example, glutamate is another neurotransmitter that influences the reward circuit and the ability to learn. When the optimal concentration of glutamate is altered by drug abuse, the brain attempts to compensate for this change, which can cause impairment in cognitive function. Similarly, long-term drug abuse can trigger adaptations in habit or nonconscious memory systems. Conditioning is one example of this type of learning, whereby environmental cues become associated with the drug experience and can trigger uncontrollable cravings if the individual is later exposed to these cues, even without the drug itself being available. This learned “reflex” is extremely robust and can emerge even after many years of abstinence.

Just as we turn down the volume on a radio that is too loud, the brain adjusts to the overwhelming surges in dopamine (and other neurotransmitters) by producing less dopamine or by reducing the number of receptors that can receive and transmit signals. When some drugs of abuse are taken, they can release 2 to 10 times the amount of dopamine that natural rewards do. As a result, dopamine’s impact on the reward circuit of a drug abuser’s brain can become abnormally low, and the ability to experience any pleasure is reduced. This is why the abuser eventually feels flat, lifeless, and depressed, and is unable to enjoy things that previously brought them pleasure. Now, they need to take drugs just to bring their dopamine function back up to normal. And, they must take larger amounts of the drug than they first did to create the dopamine high—an effect known as tolerance.

Our brains are wired to ensure that we will repeat life-sustaining activities by associating those activities with pleasure or reward. Whenever this reward circuit is activated, the brain notes that something important is happening that needs to be remembered, and teaches us to do it again and again, without thinking about it. Because drugs of abuse stimulate the same circuit, we learn to abuse drugs in the same way.

All drugs of abuse directly or indirectly target the brain’s reward system by flooding the circuit with dopamine. Dopamine is a neurotransmitter present in regions of the brain that regulate movement, emotion, cognition, motivation, and feelings of pleasure. The overstimulation of this system, which rewards our natural, life-sustaining behaviors, produces the euphoric effects sought by people who abuse drugs and teaches them to repeat the behavior.

Some people keep taking drugs because they become addicted to them. They want more—in fact, they feel like they need more. Eventually, trying to get drugs becomes the most important thing in their lives—using up their time, money, and energy, and hurting people they’re close to.

However, those people who don’t become addicted to drugs may continue to use drugs for the same reasons they started, including feeling bored or wanting to fit in with a particular group, even though drugs aren’t helping them. But whatever the reason, these people need to find healthy and constructive ways to be happy without drugs. They can do this by finding friends who share similar interests, finding healthy activities that make them happy, talking with people about their concerns, and finding friends who enjoy their company when they are not altered by drugs and alcohol.

There is no cure for drug addiction, but it is a treatable disease. Drug addicts can and do recover, but they must always be aware of their addiction and work to never fall into addiction again, which is a lifelong process. Drug addiction therapy uses behavior change or modification and sometimes includes medications that assist the user in refraining from drugs or alcohol. Like people with diabetes or heart disease, people in treatment for drug addiction learn behavioral changes that may be assisted with medications that they need to sustain for the rest of their lives. In other words, drug addicts do get better and can work to permanently refrain from drug use. Scientists know that prolonged abstinence from certain drugs allows some of the drug-induced brain changes to reverse. But addicts have to change their lifestyles and learn how to cope with the world—and they may always have to combat the urge to use drugs. It is not easy!

No one knows. A person’s genetic makeup plays a role. That’s why some people seem to get addicted almost immediately, but for others, it takes more time. There is a lot we still don’t know about who becomes addicted and why, and after how much drug exposure. We do know that each person is different, so it’s a little like playing a game of chance if you choose to use drugs. But, if you do, the earlier you stop, the more likely you will be to avoid addiction and the harmful brain changes that lead to it.

Here’s the science behind it: With repeated drug use, dopamine function in a drug abuser’s brain becomes abnormal. Because dopamine is involved in feelings of pleasure and motivation, the person feels flat, lifeless, and depressed when they are not taking the drug. Without drugs, an abuser’s life seems joyless. Now the abuser needs drugs just to bring dopamine levels up to normal levels. They need it just to get them close to where they were before they even tried drugs in the first place. Larger amounts of the drug are needed to create a dopamine flood or high, an effect known as tolerance.

By abusing drugs, the addicted person has changed the way his or her brain works. Drug abuse and addiction lead to long-term changes in the brain. These changes cause addicted drug users to lose the ability to control their drug use. Drug addiction is a disease.1

1. NIDA Commonly Abused Drugs
   2008
   View Source [↩]

No one wakes up in the morning and says, “I’m going to be an addict.” Addiction is a process – not an event. Most people who start using drugs do so with the intention of only using once or occasionally. But drugs affect the brain, so even with only occasional use, changes are happening that could lead to addiction. The “occasional” use of drugs can quickly change to frequent use and then to constant use. No one knows when the “chemical switch” goes off in your brain or who will get addicted. It’s a little like playing Russian Roulette—you just never know. The only thing we do know is that if you don’t do drugs, you definitely won’t get addicted.

It depends on the drug, but all drugs can cause negative health effects and can lead to addiction.

Addiction is defined as a chronic, relapsing brain disease that is characterized by compulsive drug seeking and use, despite harmful consequences. It is considered a brain disease because drugs change the brain—they change its structure and how it works. These brain changes can be long lasting, and can lead to the harmful behaviors seen in people who abuse drugs.1

Individuals who suffer from addiction often have one or more accompanying medical issues, including lung and cardiovascular disease, stroke, cancer, mental disorders, and obesity; and drug use can also make them susceptible to contracting HIV, hepatitis, and other diseases. Imaging scans, chest x-rays, and blood tests show the damaging effects of drug abuse throughout the body. In addition, some drugs are toxic to nerve cells and may damage or destroy them either in the brain or the peripheral nervous system.2

Some of these effects occur when drugs are used at high doses or for prolonged periods of time. However, some may occur after just one use.

In addition to health effects like those described above, drugs can also have negative social consequences that can really hurt people—being unreliable, forgetting things, telling lies, stealing money for drugs, sometimes even getting violent with people they love. Their biggest ambition becomes getting high.

While addiction may result from any drug use, there are unique health effects for each drug.

1. NIDA Medical Consequences of Drug Abuse
   Published 2007.
   View Source [↩]
2. National Institute on Drug Abuse The Brain: Understanding Neurobiology Through the Study of Addiction
   Bethesda, MD: NIDA, NIH, DHHS. Retrieved June 2003.
   View Source [↩]

“Drugs are chemicals. Every drug is different, but generally, drugs interfere with your nervous system’s basic functions. They work by tapping into the brain’s communication system and interfering with the way nerve cells normally send, receive, and process information. Some drugs, such as marijuana and heroin, can activate brain neurons because their chemical structures act like natural neurotransmitters that are found in the brain. This similarity in structure “fools” receptors and allows the drugs to lock onto and activate the nerve cells. Although these drugs mimic brain chemicals, they don’t activate nerve cells in the same way as a natural neurotransmitter, and they lead to abnormal messages being transmitted through the network.

Other drugs, such as amphetamines or cocaine, can cause the nerve cells to release abnormally large amounts of natural neurotransmitters or prevent the normal recycling of these brain chemicals, which is needed to shut off the signal between neurons. This disruption produces a greatly amplified message, ultimately disrupting communication channels. The difference in effect can be described as the difference between someone whispering into your ear and someone shouting into a microphone.”

From the National Institute on Drug Abuse’s “Drugs and the Brain.”

This is what causes the user to feel different — the signals coming and going from the brain have been altered from the way that they naturally function, leading people to have unfamiliar sensations. This can cause temporary euphoria. But it can also cause hallucinations, anxiety, paranoia, and uncontrolled behavior. It can also affect your muscles and how they function because the signals from your brain that control your movements can be altered. This can cause your respiratory (lungs) and cardiovascular (heart) systems to malfunction or fail.

Some abused substances, such as glue or butane, can cause immediate death. Cocaine, ecstasy, and methamphetamine can give even a healthy person a heart attack on the spot.

In addition to these mental, behavioral, and health-related effects, drugs also have social consequences. These can include lying to and losing the trust of friends and family; performing poorly in school; quitting academic, athletic, or social activities; losing self-control, making bad decisions like drugged or drunk driving; getting pregnant; becoming violent or placing yourself at risk to be a victim of violence; and abandoning old friendships in order to be around people who also use drugs.

Depending on the drug, some people might say they feel pleasant or relaxed. However, in many cases, these feelings may be followed by even more powerful sensations, such as depression, anxiety, nausea, confusion, lack of control, paranoia, guilt, embarrassment, hangovers, loneliness, and cravings for more drugs. People who use drugs to have fun or to forget their problems may never really learn how to find things in their lives that truly make them fulfilled or find ways to cope with difficulties, and they may keep returning to drugs because they haven’t learned other ways to be happy.