NIDA for Teens: The Science Behind Drug Abuse
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Facts on Drugs

HIV, AIDS, and Drug Abuse

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What Are HIV and AIDS?

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HIV (human immunodeficiency virus) is the virus that causes AIDS (acquired immune deficiency syndrome). AIDS is a disease of the immune system that has treatment options, but no cure, at the present time. Most people just say “HIV/AIDS” when they are talking about either the virus (HIV) or the disease it causes (AIDS).

HIV is a blood-borne virus. That means it can spread when the blood or bodily fluids of someone who’s infected comes in contact with the blood, broken skin, or mucous membranes of an uninfected person. Sharing needles or other equipment used for injection drug use and engaging in risky sexual behaviors are the two main ways that HIV is spread. Infected pregnant women also can pass HIV to their babies during pregnancy, delivery, and breastfeeding.

HIV destroys certain cells, called CD4+ cells, in the immune system—that’s the body’s disease fighting department. Without these cells, a person with HIV can’t fight off germs and diseases. In fact, loss of these cells in people with HIV is a key predictor of the development of AIDS. Because of their weakened immune system, people with AIDS often develop infections of the lungs, brain, eyes, and other organs, and many suffer dangerous weight loss, diarrhea, and a type of cancer called Kaposi's sarcoma.

The good news is that HIV isn’t the death sentence it was when the epidemic began, thanks in large part to a treatment called HAART (highly active antiretroviral therapy). HAART is a combination of three or more antiretroviral medications that can hold back the virus and prevent or decrease symptoms of illness.

Two teens sitting close together on a couch; one of whom is girl drinking from cup, and other boy watching.

How Many People Have HIV/AIDS?

HIV/AIDS has been a global epidemic for more than 30 years; today's youth have never known a world without it. In the United States, the estimates indicate that more than 1 million people are living with HIV or AIDS.

It is estimated that in 2010, more than 33,000 people were diagnosed with AIDS in the U.S. During that same year, the estimated number of HIV diagnoses in U.S. areas where this information is collected (it isn’t collected in all 50 states) was over 47,000. However, the Centers for Disease Control and Prevention (CDC) estimates that about one in five people in the United States who are infected with HIV do not know they are infected.

Can You Tell if Someone Is Infected With HIV?

You cannot tell by looking at them if someone is infected with HIV. A person can be infected with HIV for many years, and the virus may or may not progress to the disease of AIDS. A medical test is the only way to know if a person has HIV.

How Are Drug Abuse and HIV Related?

Drug abuse and addiction have been closely linked with HIV/AIDS since the beginning of the epidemic. Although injection drug use is well known in this regard, the role that non-injection drug abuse plays more generally in the spread of HIV is less recognized.

Injection drug use. People typically associate drug abuse and HIV/AIDS with injection drug use and needle sharing. Injection drug use refers to when a drug is injected into a tissue or vein with a needle. When injection drug users share “equipment”—such as needles, syringes, and other drug injection tools—HIV can be transmitted between users. Other infections—such as hepatitis C—can also be spread this way. Hepatitis C can cause liver disease and permanent liver damage.

Poor judgment and risky behavior. Drug abuse by any method (not just injection) can put a person at risk for contracting HIV. Drug and alcohol intoxication affect the way a person makes decisions and can lead to unsafe sexual practices, which puts them at risk for getting HIV or transmitting it to someone else.

Biological effects of drugs. Drug abuse and addiction can worsen the progression of HIV and its consequences, especially in the brain. For example, research has shown that HIV causes more harm to nerve cells in the brain and greater cognitive damage among people who abuse methamphetamine than among people with HIV who do not abuse drugs. In animal studies, methamphetamine has been shown to increase the amount of HIV in brain cells.

Drug abuse treatment. Since the late 1980s, researchers have found that if you treat drug abuse you can prevent the spread of HIV. When people who have a drug problem enter treatment, they stop or reduce their drug use and related risk behaviors, including drug injection and unsafe sex. Drug treatment programs also serve an important role in getting out good information on HIV/AIDS and related diseases, providing counseling and testing services, and offering referrals for medical and social services.

How Are Teens Affected?

Young people are at risk for contracting HIV and developing AIDS. CDC estimates that by the end of 2010, almost 10,000 young people, age 13 to 24, were diagnosed with HIV, and nearly 54,000 had been diagnosed with AIDS in the U.S.  In the past, most of those cases were in adolescent males. That ratio is changing as more females become infected.

In youth, as in adults, some populations are more affected than others. For example, Blacks/African Americans age 13 to 19 represent only 15 percent of the U.S. teenage population, but accounted for nearly 70 percent of the HIV infections among people age 13 to 19 in 2010. The reasons for this gap aren’t completely understood; in fact, Black/African American youth have lower rates of drug abuse than Whites and Hispanics. This remains a strong research priority for NIDA.

In general, middle and late adolescence is a time when young people engage in risk-taking and sensation-seeking behaviors that may put them in jeopardy of contracting HIV. Regardless of whether a young person takes drugs, unsafe sex increases a person's risk of contracting HIV. But drugs and alcohol can increase the chances of unsafe behavior by altering judgment and decision making.

Why Is NIDA Studying HIV and AIDS?

Since the HIV/AIDS epidemic began, injection drug use has accounted for about one-third of the AIDS cases in the United States. We now know that the poor judgment and impaired critical thinking that can result from non-injection drug abuse also can contribute in a big way to the spread of this lethal virus through risky behavior.

What Can I Do To Help?

Go to for more information on learning the link between drug abuse and HIV/AIDS. On World AIDS Day—every December 1—participate by spreading the word that drug abuse and HIV/AIDS can shorten lives. Tell your friends what you've learned and how they can avoid infection.