Between 1999 and 2013, the death rate for middle-aged white people with less than a college education in America rose markedly, in contrast with comparable demographic groups in other wealthy nations as well as with steadily dropping death rates for that group before 1999.

According to a review of statistics published Monday in the Proceedings of the National Academy of Sciences, after falling an average of 2 percent each year for the 20 years before 1999, mortality rates for white American men and women aged 45-54 who have not received a college degree rose an average of half a percent each year.

So: altogether, for middle-aged white Americans who have not received a college education, the mortality rate has risen by 22 percent since 1999. However, the New York Times reports that for those with a college education, mortality rates continued to fall.

Were it not for this reversal, a half-million more people would be alive today, the researchers, 2015 Nobel laureate Angus Deaton and his wife, Anne Case—both economics professors at Princeton—found. According to the Washington Post, the most recent precedent for such a precipitous rise in mortality rates is in Russian men following the collapse of the Soviet Union.

“Drugs and alcohol, and suicide...are clearly the proximate cause,” Deaton told the Post. “Half a million people are dead who should not be dead,” he said. “About 40 times the Ebola stats. You’re getting up there with HIV-AIDS.”

Middle-aged people are reporting more pain in recent years than they have in the past, Case found: between 2011 and 2013, a third reported chronic joint pain and one in seven said they had sciatica.

The least educated, meanwhile, reported the most pain, the worst general health, and the most financial stress, the Times reports. Since 1999, income for households headed by a high school graduate without a college degree has fallen by 19 percent.

For this demographic group, deaths from drug overdoses and alcohol poisoning rose fourfold, The Guardian reports, suicides by 81 percent, and deaths from liver disease and cirrhosis by 50 percent.

“Addictions are hard to treat and pain is hard to control, so those currently in midlife may be a ‘lost generation’ whose future is less bright than those who preceded them,” Deaton and Case wrote.

Even with the rise, though, the death rate for African Americans of this group is still greater than that for whites, the Post reports. This is because socioeconomic circumstances tend to “gang up on African Americans, who have lower education, lower incomes and race all working against them,” according to David Weir, director of the health and retirement study at the Institute for Social Research at the University of Michigan, who reviewed the study. But: “In this case, that’s not happening.”

From the Post:

Weir said economic insecurity, the decay of communities and the breakdown of families probably have had some impact on death and illness rates, in addition to the nation’s opioid epidemic and the factors the authors identified. But the study clearly shows they are not the result of diseases such as lung cancer or diabetes, which are declining and increasing slowly, respectively.

“I think it has to have something to do [with] the pain underlying it,” both physical and psychic, he said. “That is the age when people have their midlife crisis...I think it has to do with that stage of life, and physical ailments do start to accumulate at that age.

“This paper really is a question, not an answer,” he added.

“It may be that they have less hope about their ability to live a good life,” Case speculated.

Photo via Shutterstock. Contact the author of this post: brendan.oconnor@gawker.com.