Fewer patients are being prescribed both opioid painkillers and benzodiazepines such as Xanax or Ativan, a new study finds.

Taking both of these medications together increases the risk of an overdose, HealthDay reports.

Researchers at the Centers for Disease Control and Prevention collected data on prescriptions from about 50,000 pharmacies that fill almost 92% of U.S. prescriptions. They found that between 2016 and 2019, co-prescriptions of opioids and benzodiazepines dropped by almost 60%.

“Rates of concurrent prescriptions remain very high, and data from the years since COVID took hold are not even included in this study,” said Linda Richter, vice president for prevention research and analysis at Partnership to End Addiction. “It would be important to examine the role that benzodiazepine plus prescription opioid use has played in the unprecedented increase in drug overdose deaths that we’ve seen since the start of COVID, especially given the recent spike in mental health problems, especially among young adults.”