"By disaggregating monthly trends, we found that unprecedented increases in overdose mortality occurred during the early months of pandemic in the United States. At the peak, overdose deaths in May 2020 were elevated by nearly 60% compared with the previous year, and the first 7 months of 2020 were overall elevated by 35% compared with the same period for 2019. To put this in perspective, if the final values through December 2020 were to be elevated by a similar margin, we would expect a total of 93,000 to 98,000 deaths to eventually be recorded for the year. Values for the remaining 5 months of 2020 have yet to be seen; however, it is very likely that 2020 will represent the largest year-to-year increase in overdose mortality in recent history for the United States."
Joseph Friedman , Samir Akre , “COVID-19 and the Drug Overdose Crisis: Uncovering the Deadliest Months in the United States, January‒July 2020”, American Journal of Public Health 111, no. 7 (July 1, 2021): pp. 1284-1291.