A recent study from Northwestern University predicts that the opioid crisis is far from over. Overdoses in rural and urban areas will spike all across the United States, researchers find.

The study, titled, “Geographic Trends in Opioid Overdoses in the US From 1999 to 2020,” takes a look at geographic patterns of the opioid crisis, along with acceleration rates by geography.

The study found links over the past 21 years of opioid overdose deaths with geography and access to certain drugs. However, research authors say that the impending wave of the opioid crisis will not discriminate between rural and urban areas.

Every type of county—whether urban or rural—is predicted to see "dramatic" increases in deaths from opioid-involved overdoses. According to the study, opioid overdoses have reached historical levels because of the increased combination of synthetic opioids with stimulants such as cocaine and methamphetamines, a lethal cocktail that is difficult to medically reverse.

“I'm sounding the alarm because, for the first time, there is a convergence and escalation of acceleration rates for every type of rural and urban county,” said co-author of the study Lori Post, Director of the Buehler Center for Health Policy and Economics at Northwestern University Feinberg School of Medicine. “Not only is the death rate from an opioid at an all-time high, but the acceleration of that death rate signals explosive exponential growth that is even larger than an already historic high.”