In 2022, the US reached a grim peak in drug overdose deaths: Nearly 108,000 people died that year, more than twice the number who died in 2015, and more than four times the number in 2002.

Now, in what experts hope is more than a blip, the overdose epidemic that has affected every state in the nation might be showing some signs of abating.

Preliminary CDC data on the 12-month period ending in June showed that overdoses dropped about 15 percentage points from the previous period. There were still roughly 94,000 overdose deaths, signaling that the public health crisis is far from over, though a positive change could be on the horizon.

America’s overdose crisis was exacerbated decades ago by the increasing use of and addiction to synthetic opioids, such as fentanyl, that have proliferated through the nation’s drug supply.

Fentanyl was first produced in the 1960s and prescribed by doctors to people, such as cancer patients, seeking relief from severe pain. A cheaper, more potent cousin of heroin, the drug soon became a favored commodity of traffickers, who began cutting other drugs with fentanyl and drawing people addicted to prescription painkillers such as oxycodone that have become increasingly more difficult to access. As my colleague German Lopez wrote in 2017, fentanyl made America’s opioid crisis — already the deadliest drug crisis in US history — even deadlier.

So what might have turned the trend around? In the latest episode of Vox’s Today, Explained podcast we asked Lev Facher, a reporter covering addiction at STAT News.

“There’s no one event that happened about a year and a half ago that would explain this sudden significant decrease in drug overdose deaths,” says Facher. “While there’s a lot of optimism in the harm reduction and addiction medicine and recovery world, it’s cautious optimism because people don’t really know what’s happening.”

Despite that, Facher says, experts and advocates do have a few potential explanations:

Explanation 1: The drug supply is changing

The simplest explanation for the drop in overdoses could be the nature of the drugs themselves; they simply may have become less toxic and less potent. Last month, DEA Administrator Anne Milgram suggested that the agency’s crackdowns were having a direct impact on the drug supply.

“The cartels have reduced the amount of fentanyl they put into pills because of the pressure we are putting on them,” she said at the National Family Summit on Fentanyl, which gathers people who’ve had loved ones die from drug use.

Customs and Border Protection (CBP) data can’t give us the full picture of the effectiveness of cartel crackdowns, but the agency’s data shows that the rate of fentanyl confiscation at the border is hardly consistent. In January 2024, CBP confiscated 1.3 million doses of the drug. The number of confiscations dropped significantly in June before rising back to about 1.3 million doses again in August.

And data on the potency of illicit drugs is limited, given that drug-tracking systems vary from one community to another, Facher told Vox.

“The places that do have really good drug checking, there have been some changes detected in terms of the drugs people are using, but nothing that would explain this sudden drop,” he said.

Explanation 2: Drugs are being used more safely

Another explanation could be that harm-reduction efforts are working. Access to naloxone, the lifesaving, overdose-reversing drug, expanded significantly in cities across the United States in the last few years. Local governments such as Los Angeles County made the drug available at schools, churches, libraries, and jails, and everyday Americans are increasingly encouraged to carry naloxone.

Harm-reduction campaigns may have also had an impact on those who use recreational “party” drugs, who might favor stimulants but could find themselves unknowingly ingesting fentanyl if a dealer has mixed it into cocaine or MDMA. Drug testing kits like Overdrive are available for less than $15 from retailers like Amazon and provide people with step-by-step directions on testing drugs for fentanyl.

Data also suggests that the way people consume drugs might reduce the likelihood of death by overdose. Smoking fentanyl is becoming increasingly more popular than injecting it, and the former is linked to fewer fatal overdoses and blood-borne infections.

Explanation 3: The crisis has already taken the most vulnerable lives

The third explanation, floated by some epidemiologists, is the most bleak, and suggests that after hundreds of thousands of people were killed by drug overdoses in a relatively short time span, the epidemic is essentially burning itself out.

“It’s a concept called the ‘depletion of susceptibles,’” Facher said. “And that’s just to say that so many people have already died of drug overdoses that there aren’t as many drug users left to die. That’s not necessarily a mainstream theory. And even if it were accepted, it probably wouldn’t explain the full significant sudden decrease in drug deaths.”

The staggering number of deaths from the opioid epidemic, however, could be a contributing factor to declining youth drug misuse. An analysis from KFF showed a small drop in opioid misuse among high school students from 2017 to 2023. As Maia Szalavitz writes for the New York Times, “Drug epidemics are often cyclical. Younger generations witness the harm specific drugs have caused their older siblings or parents, leading them to avoid those substances.”

Can the decline be sustained?

The latest data on overdose deaths comes amid a pivotal presidential transition. While the addiction crisis is a marquee issue for both Republicans and Democrats, the incoming Trump administration includes high-level officials who’ve been intimately impacted by it.

The vice president-elect, JD Vance, has spoken extensively about how opioid addiction affected his mother and his community of Middletown, Ohio. Trump’s nominee for secretary of the Department of Health and Human Services, Robert F. Kennedy Jr., is in addiction recovery himself and his policy proposals include a network of “wellness farms” to serve as treatment facilities. It remains to be seen whether the administration will focus its efforts on addiction recovery or if it will devote more attention to law enforcement and the US-Mexico border.

“There is trepidation about a potential shift toward law enforcement and away from treatment,” Facher said. “Most of my sources talk about harm reduction, treatment prevention, and really just keeping people alive [by] meeting them where they are and getting them the services they need to live healthier lives as the cornerstone of ending this drug crisis.”