Drug overdoses spiked 18% in the United States in the first two months after pandemic stay-at-home orders began in mid-March, according to a new report.

Researchers with the Overdose Detection Mapping Application Program (ODMAP) at the University of Baltimore compared overdose statistics from January 1 through March 18, before stay-at-home orders began, with the period from March 19 through May 19. They found 62% of participating counties experienced an increase in overdoses during the mid-March through mid-May stay-at-home period.

“Overdose clusters have shifted from traditional centralized urban locations to adjacent and surrounding suburban and rural areas,” ODMAP program manager Aliese Alter told NPR. “We did find the number of spike alerts and also the duration of those spikes had increased nationally since the commencement of state-mandated stay-at-home orders.”