Nearly 42 years ago, the Centers for Disease Control and Prevention (CDC) reported a rare pneumonia in five gay men, marking the recognized start of the HIV/AIDS epidemic. While we often hear about those men’s sexuality, we hear less often about their substance use. As the 1981 report notes, one of those five men injected drugs, and all five used drugs.

The history of HIV has long been entwined with substance use. In the United States today, more than 30,000 people acquire HIV every year while the drug overdose crisis cost the lives of nearly 107,000 people in 2021. Research shows people with HIV are more vulnerable to drug overdose than are those without HIV.

Because substance use plays such a significant role in HIV transmission and in health outcomes for people living with HIV, the National Institute on Drug Abuse (NIDA) is one of the largest funders of HIV research at the National Institutes of Health (NIH). We highlight the stories behind this essential research in the video series, “At the Intersection: Stories of Research, Compassion, and HIV Services for People Who Use Drugs.”

What is a Syndemic?

Syndemics happen when two or more diseases interact to amplify each other—leading to an excess burden of disease and perpetuating health disparities. In a syndemic, environmental and social factors, like lack of quality healthcare, can make people more likely to be exposed to and experience worse outcomes from diseases. Having one health condition can also make people biologically or behaviorally more likely to acquire another illness.  However, science shows that when we address syndemic diseases together, outcomes for both can improve—especially when we integrate a variety of medical and social services with community support programs.

Approaching HIV, substance use, and other health issues through this lens can identify new opportunities to intervene that are invisible when we look at each issue alone.

Methamphetamine Use, HIV, and Mental Health Issues

A 2020 NIDA-supported study showed that as many as one in three new HIV transmissions among sexual and gender minorities who have sex with men were in people who regularly use methamphetamine. Many participants reported using methamphetamine to enhance sexual experiences, sometimes called “partying and playing.” Other NIDA-funded research shows that individuals who use methamphetamine are more likely to have sex without HIV prevention; to have mental health issues like depression, anxiety, or bipolar disorder; and are more likely to have detectable HIV viral loads and less likely to take HIV treatment and prevention medication. Fortunately, approaches that emphasize compassion and flexibility over judgment show promise in helping people who use meth achieve their health goals, take medication, and reduce their drug use or stay safer when they are using.

Substance Use, HIV, and Syringe Sharing

Since 2014, there have been at least nine HIV outbreaks associated with the sharing and reusing of syringes in communities of people who inject drugs. CDC- and NIDA-funded researchers have identified factors associated with such outbreaks, including higher rates of hepatitis C and drug overdose, poverty, and lower levels of education. Fortunately, decades of research show that syringe services programs are safe, effective ways to reduce syringe sharing—and with it, the risk of acquiring HIV. Today, many syringe services programs also offer the overdose antidote naloxone and medications for opioid use disorder (MOUD), as well as HIV testing, prevention tools, and treatment.

Substance Use, HIV, and Stigma, Criminalization, and Violence

People with HIV and substance use disorder (SUD) struggle to access quality, evidence-based healthcare. Racism, homophobia, transphobia, and HIV- and SUD-related stigma in healthcare are serious problems. Policies that punish drug use and criminalize HIV status can lead to time in jails and prisons, where access to HIV and SUD services may be limited. Immediately after incarceration, people are at greater risk of overdose and of leaving HIV care.

These factors—plus high rates of intimate-partner violence (especially among transgender and cisgender women living with HIV), childhood abuse, and other trauma—mean many people face intersectional factors leading to poor HIV and substance use outcomes. But NIDA-funded research shows promising ways forward, including integrated care that addresses the totality of people’s lives. For example, “one-stop” clinics—like the mobile health units in the NIDA-supported INTEGRA trial—test the impact of offering comprehensive services delivered by trained peer navigators who can connect with participants’ diverse experiences.

Bottom Line

Meeting people where they are to provide harm reduction and healthcare without stigma and treating the totality of people’s lives offers hope. And that hope is essential to ending the HIV epidemic.