A two-year drop, but the decline is losing speed

US overdose deaths fell through most of last year, suggesting a lasting improvement in an epidemic that has worsened for decades, federal data released Wednesday showed. The new figures run through August 2025 and continue a drop that federal officials say has lasted for more than two years, while also showing that the decline has begun to slow.

In the 12-month period that ended August 2025, the federal estimate was about 73,000 overdose deaths, down about 21% from roughly 92,000 in the previous 12-month period. CDC officials said deaths were down in all states except Arizona, Hawaii, Kansas, New Mexico and North Dakota, but cautioned that not all overdose deaths may have been reported yet in every state and that additional data later could affect the state count.

Momentum across the country, with a gap to pre-pandemic levels

Brandon Marshall, a Brown University researcher who studies overdose trends, said he saw the results as encouraging. “Overall I think this continues to be encouraging, especially since we’re seeing declines almost across the nation,” Marshall said. Even with the improvement, Marshall said the monthly death toll was still not back to what it was before the COVID-19 pandemic and not back to earlier levels before the current overdose epidemic struck decades ago.

The CDC data also represented the first update of monthly provisional drug overdose deaths since the federal government shutdown, according to the release described in the report.

How overdose deaths have shifted over time

The data illustrate how the United States’ overdose epidemic has moved through multiple eras. Overdose deaths began climbing steadily in the 1990s, first involving opioid painkillers, then waves of deaths from heroin, and more recently deaths from illicit fentanyl.

Deaths peaked at nearly 110,000 in 2022, fell a little in 2023, and then plummeted 27% in 2024 to around 80,000. The report said that 2024 marked the largest one-year decline ever recorded.

What researchers say could explain the drop

Researchers said they cannot yet say with confidence why deaths have gone down, but multiple explanations have been proposed. Those include increased availability of naloxone, the overdose-reversing drug; expanded addiction treatment; shifts in how people use drugs; and the growing impact of billions of dollars in opioid lawsuit settlement money.

Other experts pointed to research suggesting the number of people likely to overdose may be shrinking, including fewer teens taking up drugs and many illicit drug users having died. The report also described two newer theories presented in recent research.

China supply regulation and fentanyl precursor chemistry

In a paper published last week in the journal Science, University of Maryland researchers linked part of the shift to the drug supply. They said regulation changes in China a few years ago appear to have diminished the availability of precursor chemicals used to make fentanyl.

The paper relied partly on information from the U.S. Drug Enforcement Administration, which last year reported that fentanyl’s purity and dangerous potency rose early in the COVID-19 pandemic but fell after 2022. The paper also pointed to evidence that more U.S.-based Reddit users reported a fentanyl “drought” in 2023.

Peter Reuter, one of the paper’s authors, said: “we thought we could make a case.” The researchers connected their argument to steps they said the Chinese government took in 2023—at the urging of U.S. officials—to clamp down on selling substances used to make drugs. The report noted that information on exactly what China did is limited and that the paper is somewhat speculative. Reuter and colleagues also suggested that producers in Canada and Mexico may have found alternative sources.

The Maryland team’s analysis was described as drawing inspiration from earlier work by University of Pittsburgh researchers, who said regulatory changes in China concerning carfentanil were an important explanation for a dip in U.S. overdose deaths in 2018.

Pandemic stimulus checks and changes in overdose timing

Separately, the report described research by University of Pittsburgh investigators Dr. Donald Burke and Dr. Hawre Jalal. In a paper published last week in the International Journal of Drug Policy, they argued that overdose trends may be partly tied to federal stimulus checks sent to U.S. households during the COVID-19 pandemic.

The researchers tracked three rounds of stimulus payments in 2020 and 2021 and found surges in overdose deaths after each round. The report said the money eased economic hardship for many families, while some of it may also have helped people pay for illicit drugs. In their view, the end of those payments helps explain why overdoses stabilized in 2022 and began falling afterward.

Dr. Daniel Ciccarone, a drug policy expert at the University of California, San Francisco, said the two arguments appear to have merit but do not prove causation. “I personally think it’s more complicated,” Ciccarone said, describing additional trends that may be layering on top of those partial explanations.

The report also said the Maryland and Pittsburgh researchers raised questions about whether Trump administration policies could slow momentum. It said they noted that last year Trump placed sharply higher tariffs on imports from China and speculated China might ease efforts to police fentanyl precursors. They also said Trump promised a $2,000 check to Americans to help offset rising prices tied to tariffs on China, and that Burke said such payments could lead some drug users to “splurge and overdose,” while urging federal officials to consider how the money is disbursed.

Meanwhile, the report said the Trump administration canceled some 2,000 grants this week in a move expected to jeopardize programs providing mental health and drug treatment and prevention services.