Alcohol is a depressant that affects nearly every part of your body. The damage it does when you are young can impact the rest of your life. Alcohol is a depressant derived from the fermentation of natural sugars in fruits, vegetables and grains. These are brewed and distilled into a wide range of beverages with various alcohol contents.

In small doses, some of the short-term effects of alcohol are reduced tension and relaxation, but these are also accompanied by reduced inhibition (your ability to stop yourself from doing something you know you shouldn’t), coordination and reaction time – all of which put you at risk. When you drink a lot and drink fast (binge drinking), the risks go up even faster. In addition to the serious danger of alcohol poisoning, the depressant effects of alcohol can overwhelm your body’s defenses. Unable to move and think clearly, you can do risky and reckless things that are unsafe, or even lethal. Each year, approximately 5,000 people under the age of 21 die as a result of underage drinking. This includes about 1,900 deaths from car accidents, 1,600 homicides, 300 suicides, and hundreds of other deaths due to accidents like falls, burns and drownings.

Alcohol travels through your bloodstream and can damage your brain, stomach, liver, kidneys and muscles. As a teenager, your body is still developing, so damage done to it now can affect the rest of your life. Over time, drinking can wreak havoc with your body and mind.

Yes, it’s legal for people 21 and older. One reason is that alcohol can have seriously dangerous, long-term impacts on a body and brain that are still developing. Also, statistics show that more teens are killed by alcohol than by all illegal drugs combined.

Marijuana is at the center of a lot of debate, and there’s often exaggerated and even false claims made by those on each of the opposing sides. What matters is understanding how it can impact you as a teen, and that information can be hard to find in the middle of so much hype. Laws are changing, and there’s potential for new medical treatments, but these don’t erase the risks. Marijuana is green and brown mix of dried flowers, stems, seeds and leaves from the hemp plant Cannabis sativa. The main active chemical is THC (tetrahydrocannabinol), which moves quickly through the bloodstream to the brain and other organs throughout the body.

THC acts on specific targets in the brain, called cannabinoid receptors. Ordinarily, these receptors are activated by brain chemicals similar to THC that are part of a neural communication system, and play an important role in brain development and function. Marijuana over activates this system, causing impaired coordination, difficulty with thinking and problem solving, and disrupted learning and memory. Anything that impairs coordination and judgment, which marijuana does, increases a driver’s risk of being in an accident. And when used in conjunction with alcohol, the combined result is worse than either substance alone. Your brain goes through significant development during your teen and young adult years, and marijuana’s effects on the developing brain create risks unique to that time period. Following marijuana use, a teen’s decrease in cognitive abilities can last much longer than an adult’s, as long as several weeks since last use. With regular use (daily or nearly daily), the alterations to the brain caused by marijuana become prolonged by frequent recurrences, which can in-turn lead to lowered learning capabilities, a shortened attention span, and weakened verbal communication skills. There is also an association between regular and prolonged marijuana use and mental illness. A link has been demonstrated with later development of psychosis, and rates increases for those who start young. Associations have also been found with other mental health problems such as depression, anxiety, and suicidal thoughts among adolescents. It’s important to note that the nature of these links is still unclear. More research is needed to better understand whether there is only correlation, or whether causality may exist as well.

Marijuana, just like any other drug, can be addictive. It affects the brain’s reward system in the same way as all other drugs of addiction2 – and the likelihood of addiction increases considerably for those who start young.1 When marijuana use becomes daily, or nearly daily, alterations to the brain can actually lead to an inability to perceive any negative impact. In addition to the possible effects on your cognitive development, marijuana smoke is an irritant to the lungs, and frequent marijuana smokers can develop many of the same respiratory problems as tobacco smokers, such as daily cough and phlegm production, more frequent acute chest illness, and a greater risk of chest infections.

Marijuana has the potential to cause problems in your daily life, or make existing problems worse. It limits your brain’s effectiveness, slows down thinking, and impairs coordination and judgment. And while you’re young and still maturing, marijuana could have a long-lasting, negative impact on your developing brain.

When prescribed for you by a doctor, these medications can be incredibly beneficial. But when taken without a prescription or not as directed – they can become dangerous and addictive. At too high a dose, or when combined with alcohol or other drugs, many prescription drugs can also become deadly. Prescription drugs are medications legitimately prescribed by doctors to treat a variety of health problems. Some people assume that since they’re legal when prescribed by a doctor, they must be safer than illegal drugs. The truth is, these drugs require a prescription for a reason. When abused, they can be just as dangerous, and even deadly. In fact, in recent years, the abuse of prescription painkillers has resulted in more deaths than cocaine and heroin combined. The most commonly abused prescription drugs fall into three categories: Painkillers, Depressants and Stimulants.

What is it?
Prescription painkillers often contain opioids that are either naturally derived from poppy flowers, or a lab-made, semi-synthetic substitute. These drugs attach to particular sites in the brain called opioid receptors, which carry messages to the brain. When you take prescription painkillers, the message the brain receives is changed, so that pain is no longer perceived as painful. These are the same receptors that heroin binds to in the brain. Under a doctor’s direction, painkillers can be vital in relieving severe pain due to physical damage, cancer or other illnesses. Unfortunately, abusing painkillers has become a serious problem. The most commonly abused brand-name painkillers include Vicodin, Oxycodone, OxyContin and Percocet. Codeine, an opioid painkiller often found in prescription cough syrup, is also commonly abused.

The Risks
Prescription painkillers are powerful drugs that can be dangerous, or even deadly, especially when taken at high doses or combined with alcohol. A single large dose can cause breathing difficulty that can lead to death. The short-term effects of painkiller abuse can include lack of energy, inability to concentrate, nausea and vomiting.

Long-Term Effects
Because of their effect on the brain, prescription painkillers can be highly addictive when used for non-medical purposes. Even patients who are prescribed painkillers for a long time can develop a “physical dependence,” meaning that the body becomes accustomed to having the drug. Stopping the drug abruptly can cause severe withdrawal symptoms, so, any changes when using these medications must be reported to and carefully monitored by a doctor.

The Bottom Line
Painkillers are among the most commonly abused prescription drugs. Without a doctor’s prescription and supervision, short- and long-term use of prescription painkillers can lead to dangerous side effects, including accidental overdose. Combining them with alcohol or other drugs increases the risk of death from overdose.

What is it?
Doctors prescribe depressants to treat a variety of health conditions, like anxiety, panic attacks and sleep disorders. Depressants can be divided into three groups, based on their chemistry and the specific health problem they help address. These groups include barbiturates, which are often prescribed to promote sleep; benzodiazepines, like Valium and Xanax, which are prescribed to relieve anxiety; and new (non-benzodiazepinic) sleep medications, like Ambien and Lunesta, commonly used to treat sleep disorders.

The Risk
In teens, depressants can cause depression, confusion, exhaustion and irritability. And because they work by slowing the brain’s activity, they can diminish heartbeat and respiration to dangerously low levels. This is especially true when depressants are combined with alcohol or OTC medications. It’s a combination that can even lead to death.

Long-Term Effects
Depressants are highly addictive drugs, and when chronic users or abusers stop taking them, they can experience severe withdrawal symptoms, including anxiety, insomnia and muscle tremors. In fact, going “cold turkey” off of some depressants can have life-threatening consequences, like seizures, convulsions and, in rare instances, death.

The Bottom Line
Depressant drugs can make you depressed, confused and irritable. And addiction increases your chances of more dangerous outcomes, like overdose, slowed breathing and heart rate, and even death.

What is It?
Prescription stimulants affect the brain through a slow and steady release of two neurotransmitters—dopamine and norepinephrine. When prescribed and taken correctly, under medical supervision, these drugs can help treat a few health conditions, including attention-deficit hyperactivity disorder (ADHD), narcolepsy and, occasionally, depression. In treating ADHD, prescription stimulants can help regulate and normalize the dopamine and norepinephrine function in the brain, so a patient with this condition can focus better and pay more attention. Common brand-name prescription stimulants include Adderall, Ritalin, Dexedrine, and Benzedrine.

The Risk
Abusing drugs that are prescribed to treat specific medical conditions is never a good idea. And without a doctor’s supervision or monitoring, side effects can become harmful, or even dangerous. Excessive vomiting, tremors, sweating and anxiety are just some of the risks of abusing stimulants. When taken at high doses, with alcohol or with over-the-counter (OTC) medicines, stimulants can cause irregular heartbeat, dangerously high body temperatures and the potential for seizures or heart failure.

Long-Term Effects
Stimulants can be addictive. The more you take, the easier it is to get hooked. When stimulants are taken over a long period of time, stimulant abusers run the risk of developing suicidal or homicidal tendencies, paranoia and cardiovascular collapse.

The Bottom Line
Some people mistakenly believe that prescription stimulants can give them energy, help them focus and help them perform better in school. But if you haven’t been diagnosed with a condition that requires taking these drugs, and aren’t taking them under a doctor’s supervision, stimulant abuse can lead to side effects that are both dangerous and deadly.

Just because you can buy over-the-counter (OTC) drugs with few restrictions, doesn’t mean they can’t be dangerous, or even deadly, when abused.

What is it?
Over-the-counter (OTC) drugs are products that are available at supermarkets, drugstores and convenience stores. There is an incorrect but widespread belief that because you don’t need a prescription, these drugs must be less dangerous than those found behind the pharmacy counter. The fact is, it’s risky to abuse either. The most commonly abused OTC drugs include those that contain the ingredient DXM (dextromethorphan), which is used to treat cough, cold and flu symptoms. Also, OTC medications believed to help with weight loss — like laxatives, diuretics and diet pills — are sometimes abused. All of these medications can have serious and potentially fatal side effects over time.

The Risks
Both liquid cough syrups and the tablet or capsule forms of medicine that contain DXM can distort your visual perceptions and damage your sense of judgment. High doses can lead to loss of coordination, dizziness, nausea, hot flashes and hallucinations. With diet pills, it sometimes starts by trying just a few, but then can quickly turn into a full addiction. Ephedrine is one of the dangerous stimulants that can be found in diet pills. But even herbal or “natural” weight-loss products can often contain this and other ingredients that may be just as dangerous. Among the many possible side effects of diet pills are hair loss, insomnia, menstrual cycle disturbances, urinary tract infections, diarrhea, vomiting, blurred vision and anxiety.

Long-Term Effects
DXM can be so physically debilitating, it makes any activity potentially dangerous. When combined with alcohol or other drugs, it can lead to overdose and death.

The stimulants found in diet pills affect the central nervous system, increase your metabolism and make your heart beat faster. This can be especially serious for anyone with a pre-existing heart problem or high blood pressure. But even in a healthy person, diet pills can eventually cause a heart attack or stroke.

The Bottom Line
Since they’re legal and easy to find, OTC drugs are also easy to abuse. Like any medicine, they can have their benefits when taken as directed and in moderation. But there’s always the danger of taking too much, mixing them with other drugs and even overdosing. They can damage your body for life, and even cause death.