The number of fatal drug overdoses nationwide has fallen for six consecutive months, fueling hopes that the downturn marks not just a reprieve but a long-lasting shift in the tide of the addiction crisis.
Annual U.S. drug overdoses have been tracking upward for nearly four decades, and the rate of growth increased sharply in the last few years with the onset of the opioid epidemic.
But in the 12-month period ending in March 2018 — the most recent span for which data are available — the Centers for Disease Control and Prevention reported a decline of 2.8 percent in the number of overdose deaths, to an estimated 71,073 people, compared with the 12 months ending in September 2017.
Public health experts warned against drawing firm conclusions based on a half-year’s worth of data.
“After 40 years of this predictable growth pattern, we can hope that the curve is finally bending downward for good,” Dr. Donald Burke, the dean of University of Pittsburgh’s Graduate School of Public Health, wrote in an email. “But history tells us to interpret these wobbles cautiously.”
While opioids overall continue to drive the bulk of deaths, killing an estimated 48,400 people from April 2017 to March 2018, the number of fatal opioid overdoses fell by 2.3 percent compared with the year ending in September 2017. The decline was caused by a drop in the number of overdose deaths from both heroin and “natural and semi-synthetic opioids,” a category that includes most prescription opioids.
Still, ominous signs lurk in the CDC data. The ongoing addiction crisis is not limited to opioids, and cocaine and stimulants — a group that includes methamphetamine — are each now killing more than 10,000 people a year, a threshold they only crossed in the past few years.
“Whether we’re looking at cocaine or methamphetamine, we are seeing a crisis in the United States,” said Ray Barishansky, a deputy secretary at the Pennsylvania Department of Health.
Experts have predicted that any lasting downturn in overdose deaths would start with a gradual flattening and then cresting of the curve that measures fatal overdoses over time, and the data fit that pattern.
The CDC data remain a provisional count of overdose deaths, so the numbers could be adjusted as authorities continue to investigate deaths around the country.
“Three months ago I wasn’t sure the provisional deaths curve was really going down,” Dr. Daniel Ciccarone of the University of California, San Francisco, wrote in an email. “But the trend seems robust.”
Experts are not sure yet what exactly is driving the decrease, which was first noted by the Opioid Watch website, a project of the nonprofit Opioid Research Institute. But they said they are hopeful that policy initiatives at the local, state, and federal level are starting to pay off.
“There are 2 major takeaways,” said Leo Beletsky, a drug policy expert at Northeastern University. “One is that we are not out of the woods yet, since these rates are still sky high. [And] we need to be doing much more of what works to get the rates down further.”
Among other steps, advocates and health officials have pushed to expand the use of the overdose reversal medication naloxone, providing it to more law enforcement officers and people who use drugs. Having naloxone on hand can turn what would be a fatal overdose into a nonfatal incident.
And as part of a broader medical innovation law signed by President Obama in 2016, Congress approved $1 billion in spending to fight opioid addiction, funding that helped states expand treatment options, housing services, and education and workforce campaigns. Trump this week is expected to sign another addiction measure that will fight drug trafficking and expand options for accessing medication-assisted treatment for opioid use disorders.
Some clinicians are also being more cautious in their prescribing patterns, which means that fewer people are being exposed to opioid painkillers in the first place.
“It’s encouraging,” CDC Director Robert Redfield said in an interview with STAT Executive Editor Rick Berke on Tuesday, while noting that the data are preliminary.
The CDC tracks fatal overdose numbers by state, and researchers said the differences among states suggest local initiatives are having an impact as well. Many public health experts point to campaigns in Rhode Island, Vermont, and Massachusetts as models for addressing addiction, and all three states reported decreases in overdose deaths from March 2017 to March 2018 — declines that many of their neighbors did not see.
“The states that have been comprehensive and have gone after evidence-based methods are seeing the declines,” said Brandon Marshall, a Brown University epidemiologist.
Overall, Montana and Wyoming reported the biggest percentage drops in overdose deaths, though they had fewer initial overdose cases than many other states.
Beyond the policy efforts, Ciccarone, who studies drug supplies, said people who use drugs may have made “behavioral adaptations” that have led to safer drug use. Many overdoses occur when the powerful opioid fentanyl and its analogues are illicitly mixed into heroin or other drugs. Ciccarone said he and his research colleagues have found that some people are sampling their drugs before using the full amount or are speaking with others about how potent a particular supply may be before using.
Indeed, while deaths tied to synthetic opioids — the classification that includes fentanyl — continue to rise in the CDC’s tracking, their growth rate has slowed in recent months.
Epidemiologists said they look to CDC’s provisional data each month to determine if the bend in the curve will hold and to see which state responses should be studied further. But as promising as the latest slowdown might be, with each fewer fatal overdose representing a life saved, experts have seen “flattening periods” in the past that did not change the overall trajectory of overdose deaths.
Burke, of the University of Pittsburgh, was the senior author on a paper published last month in Science, in which researchers outlined how “the U.S. drug overdose epidemic has been inexorably tracking along an exponential growth curve since at least 1979.” They described an epidemic that is made up of many different drug “subepidemics.”
The “current opioid epidemic may be a more recent manifestation of an ongoing longer-term process,” the study said.
This story has been updated with a quote from the director of the CDC.