Commentary on the coronavirus pandemic: Anticipating a fourth wave in the opioid epidemic.

Experiencing the COVID-19 pandemic simultaneously with the U.S. opioid epidemic is anticipated to have a profound mental health impact on some of our most vulnerable populations. Recent federal and state regulatory changes have been made under the state of emergency in order to ameliorate the some of the challenges faced in maintaining access to substance use and addiction services during such times. There are currently considerable limitations in quantifying the impact of COVID-19 among those with substance use disorders, however, it is imperative that health care systems continue to serve this population in order to prevent associated morbidity and mortality.