A new county-level study from Pennsylvania State University suggests a relationship between the epidemic of opiate addiction tearing apart many U.S. communities and the level of support for Donald Trump in November's election.

The president-elect performed better than Mitt Romney, the Republican nominee four years ago, in counties with the highest drug, alcohol and suicide mortality rates, the study says.

Shannon M. Monnat, a rural sociologist and demographer at Penn State, found the trend to be true nationally but especially pronounced in the industrial Midwest and the New England states. She built a database to compare the mortality numbers and vote totals from 3,106 counties in order to draw her conclusions.

In the Rust Belt states, Trump ran ahead of Romney an average of 16.7 percentage points in the quarter of counties with the highest mortality rates due to substance abuse and suicide, compared to 8.1 percent percentage points in the quarter of counties with the lowest such rates. In New England, Trump did worse than Romney, a former Massachusetts governor, by 3.1 percentage points in the lowest mortality counties but outperformed him by an average of 10 points in the highest mortality counties.

Monnat notes that counties with the most economic distress and large working-class populations tend to have higher rates of death by opiate overdoses, alcoholism and suicide than counties that are more prosperous. The "diseases of despair" are symptoms of broad social decay caused by deindustrialization, she writes.

"In many of the counties where Trump did the best, economic precarity has been building and social and family networks have been breaking down for several decades," Monnat says. "In these places, there are now far fewer of the manual labor jobs that once provided livable wages, health insurance, and retirement benefits to those without a college degree. Downward mobility is the new normal."

Correlation is not causation, and there were many factors that drove voters to Trump, the real-estate mogul with no political experience and the promise of radical change. But Monnat says that, even using statistical models with as many as 14 demographic and health variables, "the drug, alcohol and suicide mortality rate remains a significant and positive predictor of Trump over-performance."