New government data shows the United States saw a 15% increase in overdose deaths in 2021, driven by fentanyl and methamphetamine, The New York Times reports.

Overdose deaths neared 108,000 last year, according to the data from the Centers for Disease Control and Prevention. Deaths from fentanyl and other synthetic opioids rose from 58,000 to 71,000. Deaths from meth and other stimulants increased from 25,000 to 33,000.

Many overdose deaths last year appeared to result from people combining fentanyl and meth, according to state health officials.

“There’s an intertwined synthetics epidemic the likes of which we’ve never seen,” said Dan Ciccarone of the University of California, San Francisco, who has just started a study of the combination of opioids and meth. “We’ve never seen a powerful opioid such as fentanyl being mixed with such a potent methamphetamine.”