Researchers have found that U.S. overdose death rates declined dramatically between 2023 and 2024, marking the first recorded drop in all four waves of the nation’s overdose crisis.
Critically, the decrease was largely driven by falling deaths involving illicit fentanyl, both alone and in combination with stimulants.
Experts describe the U.S. overdose epidemic as unfolding in four waves: prescription opioids, heroin, fentanyl, and fentanyl combined with stimulants, such as methamphetamine or cocaine. The new findings show that the fourth wave declined for the first time in 2024.
Despite the encouraging trend, researchers warn that overdose deaths involving stimulants without fentanyl, as well as xylazine-related deaths, continue to rise.
“We are seeing a historic shift in the overdose crisis,” said Joseph Friedman, MD, PhD, MPH, resident physician in the Department of Psychiatry at UC San Diego School of Medicine and the study’s first author. “But this is not the end. The substances involved are changing, some parts of the crisis are still growing, presenting new challenges. We need to avoid interpreting declining national numbers as a sign that the crisis has been solved.”
Up and down
The study, published in Addiction, found that the national overdose death rate fell by 24.4% between 2023 and 2024, dropping to 23.7 deaths per 100,000 people. Deaths involving fentanyl without stimulants fell from 31,193 in 2023 to 19,673 in 2024, while deaths involving fentanyl combined with stimulants dropped from 41,583 to 28,062.
According to the study authors from the University of California San Diego, possible explanations for the decrease include a reduced number of susceptible individuals, greater awareness of fentanyl risks, expanded availability of naloxone, changes in drug use behavior and possible disruptions in the illicit fentanyl supply chain.
On the other hand, the study also showed deaths involving stimulants without fentanyl continued increasing, rising from 18,142 deaths in 2023 to 18,907 in 2024. These deaths accounted for 17.3% of overdose fatalities in 2023, but grew to 23.8% in 2024. Xylazine, a veterinary sedative increasingly found in the illicit drug supply, was also implicated in a growing share of fentanyl-related overdose deaths.
The UCSD team warns that if these trends continue, stimulants such as methamphetamine and cocaine may soon surpass opioids as the defining addiction-related public health challenge in the U.S.
Addressing the numbers
Even with the recent decline, overdose deaths in the United States remain extraordinarily high compared with other countries. For example, in 2023, the U.S. drug overdose mortality rate was 23.1 deaths per 100,000 people, representing nearly 80,000 annual fatalities. Meanwhile, in the European Union, the mortality rate due to overdoses in 2023 was estimated at 24.7 deaths per million people.
Researchers say continued investment in addiction treatment, harm reduction programs and targeted public health interventions will be essential to sustaining progress and reducing persistent inequities.
The UCSD research team says the next phase of their research will focus not only on lowering overall deaths, but on making sure those gains reach the populations that have been hit hardest—especially addressing racial and ethnic disparities.